Why is My Car’s A/C Blowing Hot Air Out of The Vent?

#driveyourlife

The air conditioning system in your car is designed to cool down the air in the cabin of your vehicle to keep you comfortable on a hot day. It’s something that we often take for granted until it’s a hot day and you ask, ” Why is my car’s A/C blowing hot air?” When you only get hot air instead of cold air, it can be frustrating and extremely uncomfortable. If your air conditioner blows warm air, it is important that you get it looked at as soon as possible so you can continue driving in cool comfort. In this article, we’re going to look at how your Car’s A/C creates the cold air so you can more accurately diagnose what’s going wrong.

How Does a Car’s A/C Work?

Your car’s A/C system is one that operates a little differently than you might think. Instead of actually creating cool air, it instead removes the heat and moisture from the air inside of your car, leaving you with cooler feeling air. In technical terms, the cool air is created by blowing air from either outside your car, or from the cabin over cold coils. This cools down the air before it gets blown out of the ventilation system into your car to keep you comfortable. Most systems are designed to blow very cold air, between 32 and 40 degrees! These cooling coils, called the evaporator, is where the actual cooling of the air happens. These coils are cooled by cold refrigerant flowing through them.

Most cars today use a refrigerant called R-134a which is a special refrigerant designed to work at the temperatures and pressure standard in a car’s A/C system.  As the cold refrigerant passes through the evaporator it absorbs the heat in the air which warms up the refrigerant.  This warmer refrigerant now needs to be cooled back down so your A/C system can continue to operate.  This is accomplished by first compressing the refrigerant to a high pressure which also heats it up to a high temperature.

This hot refrigerant is then cooled down by running it through the condenser.  The condenser is cooled by ambient air in the front of your car just like the coolant in the radiator is cooled.  On most cars the condenser is actually in front of the radiator and gets cooled first to make sure your A/C system gives you consistently cool air.  This high pressure, now cooled, refrigerant is then allowed to expand quickly as it passes through an orifice or expansion valve.  The expansion valve is a simple device that takes advantage of the fact that quickly expanding liquids and gases get cold.  The process of liquids and gases getting cold during expansion is a scientific phenomenon you can prove by using an entire can of spray paint in one sitting and seeing how cold the can gets.

Now the cold, low-pressure refrigerant can return to the evaporator to cool it and along with it, more air keeping your car comfortable.  There are a few other components in the system like temperature and pressure sensors, hoses and the dryer or accumulator.  The dryer is where any moisture is removed from the refrigerant, the refrigerant is filtered to make sure it all enters the compressor as a gas, and the oil for the system is equally distributed through the refrigerant passing through.

Common A/C Problems & How to Fix Them

car AC blowing hot airIf your car’s air conditioner isn’t working properly and is blowing hot air then one of these systems isn’t doing its job properly. Getting to the root of the problem can take some time and effort, but we have simplified the process by providing you with the most common A/C problems along with how to resolve these problems once they’re discovered.

The Evaporator or Condenser is Clogged

Since there are two components that require air to be moving through them, the evaporator and the condenser, it is possible one or both of these are clogged and not getting the proper air flow.  Check the front of your vehicle for debris, the engine cooling fans for proper operation, and your cabin air filter for debris and dirt.  The refrigerant in your system also needs to be able to flow properly through the system.  Check your compressor for proper operation, clogs in your system and the proper amount of refrigerant.  All of these can be checked by observing the pressures around the system both before and after the compressor and all the other components.  This can be done with set of A/C gauges to measure both the high and low pressure sides of your A/C system.

If you find unusually high pressure before any particular components and unexpectedly low pressures after them, there is a good chance there is a clog in that component.  If this is the case, you will most likely find the clog in the accumulator or the condenser.  If you don’t have a large enough pressure increase across your compressor you may be in need of a new AC compressor.  If you have lower than expected pressures on the low pressure side of your system, may simply have a low refrigerant level.

Electrical System Issues means AC blowing hot air

Let’s keep it simple since your A/C blowing hot air can be complex. There are so many different wires, fuses, pressure switches, and more that all work together to start blowing cold air into your car. Therefore, if just one of these components stop functioning, it is very likely that your entire system will shut down. For a novice, the place to start here is by doing a visual inspection of the wiring to see if there are any that are damaged or frayed. Repair or replace any damaged wires if you can find them, if not, you may have to take the car to your dealer or a mechanic who will have the expertise to diagnose the specific issue.

The A/C System Needs Recharging

If you do not have enough refrigerant in your car’s A/C system the compressor may not be able to raise the system pressure high enough for the expansion valve to be effective in cooling down the refrigerant.  Due to the high pressures of your air conditioning system and the volatile nature of the R-134a refrigerant used, it is not uncommon for some of the refrigerant to leak out over time causing a low pressure condition in your system.  If you discover this to be the reason why your car air conditioner is blowing hot air add Red Angel A/C Stop Leak to your vehicle’s air conditioning system to seal any leaks no matter how small they are before you recharge the system.

Red Angel A/C Stop Leak One Shot comes in an easy to use aerosol can that can be installed quickly and easily without any tools and also contains 2.5 ounces of R-134a to help bring your system back up to normal operating pressure.

BlueDevil Products can be found on Amazon.com or at AutoZone, Advance Auto Parts, O’Reilly Auto Parts, NAPA, and other major auto parts retailers.

324 responses to "Why is My Car’s A/C Blowing Hot Air Out of The Vent?"

324 Comments

  1. Dave Abekein on June 2, 2015 at 6:10 pm

    Why don’t any of the email addresses published on the BD website work?

    • BlueDevil Pro on June 4, 2015 at 11:53 am

      Dave-

      All of the email addresses work. We receive and send multiple emails daily. I will email you now directly.

      Make you you are using the ending @gobdp.com rather than @bluedevil.com

      Thanks!

      -BDP

      • Roy Thompson on May 13, 2016 at 3:50 pm

        I have a CLK430 Benz an it blows our hot air when I come to a stop

        • BD Auto Pro on May 20, 2016 at 10:06 am

          Roy,

          Thanks for your question about your CLK430. More often than not, when a car is blowing hot air only at a stop, the problem is with the electric cooling fans. Those fans should kick on when you turn your air conditioning on to keep enough air moving through the condenser while you’re stopped. If you don’t see or hear these fans try checking electrical connections, fuses and relays. If the fans are coming on, the problem is most likely with your air conditioning system and you should have the pressures around the system checked to see what components are malfunctioning or if you have a leak.

          Thanks again for your question!
          -BD Auto Pro

      • Johnathan carter on May 10, 2018 at 4:58 pm

        I have a 2006 Buick lacrosse the AC blows cold then gets hot after a few min returns to cold what will most likely be my problem

        • BD Auto Pro on May 10, 2018 at 9:02 pm

          Johnathan,

          Thanks for your question about your 2006 Buick Lacrosse. Most likely, you either have an overfilled system or broken condenser fans. If your system has too much refrigerant in it, the pressure will quickly get too high when you first turn it on causing it to trip off on over-pressure then as things cool down it would kick back on. Similarly, if your AC condenser fan isn’t working, your air conditioning would blow cold until the condenser got heat soaked then it would stop working until you were up to cruising speed then the air blowing over the condenser while driving would cool it down and keep things working.

          Thanks again for your question!
          -BD Auto Pro

        • Brian on October 16, 2021 at 7:08 pm

          I have a 2004 Cadillac Deville. Hot air blows at the feet on the passenger side even if the climate control is turned all the way off.

          • BlueDevil Pro on October 18, 2021 at 10:06 am

            Brian-

            Thank you for asking about your Cadillac Deville. The heat you are feeling could be coming from the engine, as air is being sucked in from outside the vehicle. This more than likely would not be the case if the climate control was on, as climate control would be able to blow the air at whatever desired temperature you set. You can also try selecting the recirculation setting, as this would not be drawing air from outside the vehicle to blow from out of the vents.

            Thank you!

            -BDP



      • Steven on July 15, 2021 at 7:47 pm

        I have a 2002 Toyota Camry xle, blend door actuator replaced cabin filter, blower motor and clutch relay replaced, recharged the system and still blowing warm air heater works fine ,just no cold ac @gobdp

        • BlueDevil Pro on July 16, 2021 at 8:57 am

          Steven-

          Thank you for asking about your Toyota Camry. Based on your description and the work you’ve had done, we’d recommend measuring the PSI from the low and high side. The PSI readings could help point you in the right direction as to what the issue is. Also, if you have not done so already, it is always a good idea to flush out the A/C system anytime you are replacing components. This way, you are not contaminating the new parts with debris/dirt left behind.

          Hope this helps!

          -BDP

    • Mercedes Baker on June 27, 2017 at 3:09 pm

      I have a 2014 Nissan Altima and I does blow cold air but when it’s too hot outside like in the 90s it blows hot air

      • BlueDevil Pro on June 27, 2017 at 3:18 pm

        Mercedes-

        Thank you for asking about your Nissan Altima. Based on your description, it is possible your fresh air/recirculating motor is faulty, as it sounds like it is only pulling in hot air. We recommend a trip to an A/C specialist to check on the motor and make sure it is connected properly.

        Thank you!

        -BDP

        • mary delgado on July 31, 2017 at 6:57 am

          i have a toyota camry LE And had the alternator changed by a friend. my a/c was working great when the freon was accidently released. now my a/c dosent work! it blows hot air, had hoses flushed out, new freon added per specs. still hot air comes out! high pressure very high and low pressure is very high! mechanics said never seen this before. whats wrong with my a/c? HELP. MARY D. from visalia, ca

          • BD Auto Pro on August 3, 2017 at 2:48 pm

            Mary,

            Thanks for your question about the air conditioning in your Toyota Camry. The symptoms you’re seeing in your air conditioning system could indicate that the system is overfilled with refrigerant so you could try checking the specifications again for the amount of refrigerant your car takes to make sure the right amount was installed. If you’re sure you’ve got the right amount of refrigerant, it sounds like you may have some clogs in the system from when it was accidentally opened. Clogs often form in the expansion valve or the dryer which could cause the indications you’re seeing. Unfortunately, you would need to replace those components to remove the clogs.

            Thanks again for your question!
            -BD Auto Pro



        • Erika on May 21, 2018 at 3:33 pm

          I have a similar issue and would like to add detail. My 2014 Nissan Altima’s air conditioner works normal when it’s cool out, like in the morning. Once I leave work, the temperature outside is 90+, my air conditioner will blow cold only when I am accelerating. But once I’m idle-ling, it blows hot air again. I’ve checked, it has freon. Any suggestions on what this could be?

          • BD Auto Pro on May 22, 2018 at 9:16 am

            Erika,

            Thanks for your question about your 2014 Nissan Altima. It’s possible that your system has too much refrigerant in it so the pressure is getting too high when you are driving and your compressor is spinning quickly with higher engine RPMs. Too high of a pressure can trip your system off on an over-pressure fault and cause it to start blowing hot air. To prove this you would have to check your AC high side pressure it a higher engine RPM after your car has been warmed up.

            Thanks for your question!
            -BD Auto Pro



        • Harold Spradlin on May 15, 2022 at 6:18 pm

          2008 grand marquis
          Engine light came on ..
          Changed t stat .. all good.. except hot air coming out of vents.
          Turned on ac , hot air , checked compressor, clutch engagement. Tried charging ac , reads full, checked radiator, seems good . Any ideas?

          • BlueDevil Pro on May 16, 2022 at 8:52 am

            Harold-

            Thank you for asking about your Mercury Grand Marquis. Does the engine light still come on after the thermostat replacement and a/c recharge? Is the vehicle overheating at all? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

            Thank you!

            -BDP



    • Amechi orewa on December 16, 2018 at 10:15 am

      My Lexus RX 350 2008 model aircondition was not cooling well but after topping gas it started blowing hot air

      • BlueDevil Pro on December 17, 2018 at 10:17 am

        Amechie-

        Thank you for asking about your Lexus RX 350. Did you mean topping off the refrigerant or adding fuel? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

        Thank you!

        -BDP

        • Bill Hogue on July 17, 2023 at 9:11 am

          I have a 2004 Dodge Dakota and the a/c will blow cool air one day and hot air the next. Can you tell me what I might check.

          • BlueDevil Pro on July 17, 2023 at 1:28 pm

            Bill-

            Thank you for asking about your Dodge Dakota. In a situation like this, the best place to start would be to get a set of gauges and measure the low side and high side PSI’s. The PSI readings will point you in the right direction as to what is causing the intermittent cool air. Most a/c issues arise from refrigerant leaks, which the PSI readings would also be able to indicate whether the system is undercharged.

            Thank you!

            -BDP



    • Coty Noel on November 23, 2020 at 1:06 pm

      My 2010 VW Routan blows cold air on drivers side vents only. Passengers side and rear is hot. What could cause this

      • BlueDevil Pro on November 24, 2020 at 8:59 am

        Coty-

        Thank you for asking about your Volkswagen Routan. If you are getting consistent cold air blowing out of the drivers side and the passengers side isn’t blowing out that same cold air, you may have a defective blend door actuator. If the system was low on refrigerant, you wouldn’t be getting consistent cold air blowing out what so ever. Having the blend door actuator replaced should resolve the issue.

        Thank you!

        -BDP

    • Katir on March 21, 2022 at 4:34 pm

      2006 for Taurus. Car blows hot air then after about 20 or 30 minutes starts blowing cold. Has been charged w freon.

      • BlueDevil Pro on March 22, 2022 at 8:31 am

        Katir-

        Thank you for asking about your Ford Taurus. Does this happen every time you put the a/c on or is it only when the ambient temperature is above 85 degrees? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

        Thank you!

        -BDP

    • Jennifer Malone on May 9, 2022 at 7:44 pm

      I have an 02 lasabre that pushes hot air off the engine when the heat is off and when I set the temp to cold, it blows hot air

      • BlueDevil Pro on May 10, 2022 at 8:18 am

        Jennifer-

        Thank you for asking about your Buick Lesabre. The most common conclusion for your description is that the a/c is low on refrigerant. Nothing really operates properly when the level of refrigerant is below the proper level. Try recharging the A/C to see if that helps.

        Thank you!

        -BDP

    • Steve tien on January 25, 2023 at 8:40 pm

      Dave, I have a 2014 Infiniti qx60. Hot air started blowing today. I bought some refrigerant but when I put the gauge on it showed red, while car was running. Now I did this after a multi hour trip so not sure that had anything to do with it. Most articles I read say the problem is over filling. The compressor seems to be working. Any other thoughts before I take it in? Thx.

  2. dre on September 7, 2015 at 10:40 am

    i have a 97 buick park avenue put 2 cans of freon in it and the next day it was blowing hot air again do the stop leak fix big leaks as mine thats not even lasting a day

    • BlueDevil Pro on September 23, 2015 at 8:45 am

      Dre-

      It sounds like your leak is a little bit too extreme for what the Red Angel is intended to fix. Your best bet may be to take the Buick into an A/C specialist to be repaired.

      Thank you!

      -BDP

  3. Ged on November 15, 2015 at 9:01 am

    Hello,

    I have problem with my ford cougar 1999 A/C Does not matter what settings is on, it always blows cold, freezing cold air. Its like the setings stuck in cold air setings. When i change settings, i hear the valves moving, changing and air flow is changing too, but it always blows only cold air. I checked the pressure of low and high pressure valves and they are correct (Low just below 50 and hig below 200). When i start car and turn a/c on to warm or cold settings, the pipes around engine gets frozen white. Antifreeze levels are full to the max point. I have ordered thermostat, will try to change it, but not sure if that will help. I never hade this problem before, so have no clue what to check. The compressor looks like it working as it should be. Any ideas what can be wrong?

    Thanks

    • BlueDevil Pro on December 21, 2015 at 11:42 am

      Ged,

      Thanks for your question about your AC. It sounds like the problem is with your heater not your AC. Even if your AC is on, your heater should still warm the air back up. Your problem could be in your ventilation system. Even if the motors are moving the flapper door that should direct air over the heater core may not be moving. To check this, you’ll have to dig into your vent ducts and test that flapper door. The other problem is that your heater core could be clogged, or your thermostat stuck open. If your thermostat is stuck open, you’d notice the temperature staying very low in your car for a long time after starting. If your heater core is clogged, try using BlueDevil Radiator Flush (available here: http://store.gobdp.com/radiator-flush-00204/).

      Thanks again for your question!
      -BD Auto Pro

    • Brooke Crites on August 7, 2020 at 10:29 pm

      I Have A 2003 Chevy Suburban 1500 LS. Air Has Been Working Just Fine Since The Last I Drove It! (ONLY* 2 Days Ago, It Is A Daily Driver) I Got In Truck Today .. Turner Air On…. IT BLOWS Hot!! I Noticed A Was A Little* Low On Antifreeze…. Got That Done It Still Wouldn’t Work…. So I Bought Freon… Tried That.. Can Never Turned ” Cold ” ( Autozone Said It Was Supposed To Turn Cold )But Supposedly It Was ” Low” We Put It In There Til It Read ” Full “… AIR STILL DOESNT Work!!! I’ve Wasted $60 For NOTHING. What Else Could It Be?

      • BD Auto Pro on August 12, 2020 at 10:25 pm

        Brooke,

        Thanks for your question about your 2003 Chevy Suburban. If you’ve added refrigerant and your air conditioning still isn’t working the next step would be to measure the pressures in your system. That will help you determine if a leak has caused your air conditioning to stop working or if you’ve got an electrical problem or a mechanical problem. Measuring the pressures will also help you tell if your added too much refrigerant or not.

        Thanks again for your question!
        -BD Auto Pro

  4. cyprian on April 22, 2016 at 11:15 am

    I have a 2006 Skoda Octavia 1.9TDI. On hot days, when i get into the car and turn on the AC, nothing happens. I just get warm air flowing out of the vents. After 20 or thirty minutes of driving, when i turn of the AC and turn it back (1 minute delay), the AC starts working. Also, it doesn’t cool on such hot afternoons unless the blower speed is set to position 2 or 3. I rarely use position 4 cos its noisy. However on cool evenings and mornings, the AC blow cool air instantly. The refrigerant is fully recharged. My condenser is a new one. .
    Sometimes when i turn the blower speed down to 1 or adjust the temperature (from 18 degree Celcius to a comfortable 22 degrees Celcius), the AC cuts off and doesn’t come on again.
    I have checked the cabin air temperature sensor and it works fine and i have had to change it to see if things will improve but it didn’t change anything.

    • BD Auto Pro on May 13, 2016 at 9:11 am

      Cyprian,

      Thanks for your question about your Skoda Octavia. There are a few possible problems you might be having. First, you might have a faulty pressure switch in your system. On warm days the pressure in your AC system is higher and if your pressure sensor is faulty and reading too high it might trip the system off on warmer days. Second, it could be that your AC clutch is malfunctioning and on warmer days, or when more load is on the system it fails to engage the AC compressor which would cause your system to not operate correctly. Lastly, there could be a clog in your system that only causes problems on warmer days when pressures are high.

      Thanks again for your question!
      -BD Auto Pro

  5. dave smith on May 4, 2016 at 12:56 am

    I have a 2004 Chevy Tahoe that intermittently blows hot air when the A/C is on. I hear a clicking sound for a few minutes and then the hot air comes out. Just by accident, I found that if I pull over and turn the car off and then turn it back on, the A/C resumes. Any ideas of what is causing this problem?

    • BD Auto Pro on May 13, 2016 at 9:20 pm

      Dave,

      Thanks for your question about your Chevy Tahoe. The problem you’re having sounds like it’s actually a problem with your ventilation control unit. The clicking sound you’re hearing is probably the air blend doors moving or trying to move behind the dash until the blend door moves to the “hot” position directing the air over your heater core so it comes out of the vents warm. When you shut your car off for a short time it resets the unit. You can try pulling the fuse for heater control unit for a few minutes, then replace it and turn you truck on the set your ventilation control unit into calibration mode. If that doesn’t fix the problem then the servo motor or the door placement indicator is probably bad sending a bad signal to the control unit.

      Thanks again for your question!
      -BD Auto Pro

  6. eugene wolcott on July 5, 2016 at 9:56 pm

    hi i have a 2007 ford freestyle. The A/C blows hot/ warm at idle and driving. I can hear the compressor turn on when I hit the button. The low pressure port is 100 lbs which sounds high to me and when I checked the high pressure port a bunch of yellow greasy liquid came out any ideas on how to solve this? I am a DIY guy but have little experience with A/C and trying to learn.

    • BD Auto Pro on July 16, 2016 at 4:19 pm

      Eugene,

      Thanks for your question about your Ford Freestyle. Depending on if your compressor was running or not, 100psi does sound high for your system. To check the high pressure side you’ll need a set of mechanics AC gauges. With a set of gauges you should be able to tell if your system is overfilled with refrigerant, if the compressor is working properly and if there is a clog in your system which are the three most likely problems you’re having based on your description.

      Thanks again for your question!
      -BD Auto Pro

  7. Jana Peters on July 7, 2016 at 5:08 pm

    I have 2008 Nissan Altima. I put Freon in and it worked for like a month, then hot air again. I took it to a shop and they fixed a leak and it worked perfect for 5 days now today it was hot air again after 45 mins it was finally cold. Could this be a more serious issue like needling to replace the condenser and compressor?

    • BD Auto Pro on July 16, 2016 at 4:54 pm

      Jana,

      Thanks for your question about your Altima. Based on how long it takes for your AC to get cold, it sounds like you’ve got a clogged component in your system, possibly the expansion valve or the dryer. It is possible that your compressor is going bad as well, but less likely. To check for all of these problems you’ll need check the high side pressure in your system. If it is too high then you’ve most likely got a clog, and if it is too low then your compressor may be failing.

      Thanks again for your question!
      -BD Auto Pro

      • Odonis jones on July 5, 2017 at 6:18 pm

        I have a c230 Mercedes benz 2007 and it had cold air it was blowing it out really good then one day it stop and nothing but hot air came out so I put in about three freon cans in and nothing still it still is blowing hot air out I have no clue what’s wrong with it

        • BlueDevil Pro on July 6, 2017 at 10:42 am

          Odonis-

          Thank you for asking about your Mercedes Benz c230. An improper level of refrigerant can cause the system to not give you proper cooling. Whether the refrigerant is too low or there is too much refrigerant, it could cause the issue you have described. We recommend checking the refrigerant level and adding/draining refrigerant as needed.

          Thank you!

          -BDP

  8. Levi on July 11, 2016 at 8:02 pm

    I have a 2003 Chevy Silverado my AC was blowing cool air not cold up until a couple days ago. I bought some air conditioning recharging fluid put the gauge on there so that it was a little low. Then I added some until the gauge read in the blue where it should be but now my system only blows hot air I have no clue why. Somebody help me please.

    • BD Auto Pro on July 16, 2016 at 5:39 pm

      Levi,

      Thanks for your question about your Chevy Silverado. The gauges on the refill AC cans are not vehicle specific so it is possible that your system is now overfilled with refrigerant. That could cause it to trip off on over pressure or for your dryer to not be able to keep up with the extra refrigerant which would also cause your system to shut down.

      If you use a recharge can that has a particulate leak stop agent you could also have a clog in your system which would keep it from operating properly. Lastly, you could have a large leak in your system and even though you just added refrigerant, it’s all leaked out so you could try checking the low side pressure with the gauge again just to verify you don’t have a large leak.

      Thanks again for your question!
      -BD Auto Pro

    • Bomai Kaupa on October 1, 2020 at 9:38 pm

      Hi
      I have a toyota Mark 2 grande 2001 model.
      Heat comes out from the driver side. Every time i accelelrate heat comes out. The more i accelerate the more heat is peoduced. What could be the cause?

      • BlueDevil Pro on October 2, 2020 at 10:23 am

        Bomai-

        A good place to start would be to make sure the system has the appropriate amount of refrigerant. If you are able to get the high side and low side psi, this may help to point you in the right direction as to what the problem is. If it turns out the system is low on refrigerant, we recommend using the Red Angel A/C Refrigerant Stop Leak to help stop the loss of refrigerant and return the A/C to normal functionality.

        Thank you!

        -BDP

  9. Dianne McGhee on July 13, 2016 at 6:53 pm

    I have a 2007 Toyota Camry. My air conditioner is acting crazy. It blows cold air when it’s not real hot outside like 75 degrees. Then when it gets hot outside it blows warm air. Mechanic measured freon and it was OK. Do you know what the problem could be?

    • BD Auto Pro on August 11, 2016 at 2:18 pm

      Dianne,

      Thanks for your question about your Camry. Based on your description your system could be over filled with refrigerant or you may have a faulty pressure or temperature switch. On warmer days, your AC system pressures get very high so if it’s overfilled it could be tripping off on an overpressure causing the warm air and if you have a bad pressure or temperature sensor it could be inadvertently shutting your system down because the sensor is reading incorrectly.

      Thanks again for your question!
      -BD Auto Pro

  10. Tiffany on August 17, 2016 at 11:02 am

    I have a 2000 buick Century when you turn on the a.c. it blows warmish air but when switched to heater it only blows warmish air and doesn’t heat up either, What could cause this? I bought a.c. recharge cause it was a little low and that didn’t help at all. Checked all other liquids and they are where they should be also. Please help

    • BD Auto Pro on September 3, 2016 at 6:08 pm

      Tiffany,

      Thanks for your question about your Buick Century. It sounds like your problem is with your ventilation system. When you change the temperature switch it should move an air blend door which directs air either over your AC cooling coils or your heater core. If the motor that moves this door, or the door itself is damaged then it would cause the same temperature air to blow out of the vents no matter what. unfortunately to get to the air blend door to check it you have to remove a significant amount of your dashboard and air ducting.

      Thanks again for your question!
      -BD Auto Pro

      • Haruna Thomas on July 30, 2020 at 4:03 am

        I have 2006 Bmw e60 the a/c is blowing hot instead off cool. I was advised to free all the refrigerant in it and refill with two keg of 390kg which I did. At the point of refilling it was cool. After five minutes drive the system started blowing hot again with refrigerant on the normal gauge. Pls what can I do?

        • BlueDevil Pro on July 30, 2020 at 8:53 am

          Haruna-

          Thank you for asking about your BMW E60. Based on your description, it’s possible you are experiencing a slight refrigerant leak. Keep in mind, the system doesn’t have to be empty or close to empty for it to be blowing warm air. Even if the system is a little low on refrigerant, that could cause it to blow warm again. We recommend using the Red Angel A/C Refrigerant Stop Leak. This should return the A/C to normal operation.

          Thank you!

          -BDP

  11. Missie Miller on September 11, 2016 at 10:39 pm

    My air conditioner was blowing cold air. We replaced the thermostat in my 2002 Ford Taurus and the air flow coming from the air conditioner immediately began blowing warm air. We checked the freon and the compressor, and everything seems fin.

    • BlueDevil Pro on September 15, 2016 at 9:21 am

      Missie-

      Thank you for asking about your Ford Taurus. Based on your description, you may have some kind of a restriction in the system, not allowing proper circulation. We recommend bringing the vehicle to an A/C specialist for an A/C Flush. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!

      -BDP

  12. Denise on September 17, 2016 at 7:23 pm

    My 2010 Toyota corrolla ac was running fine…yesterday when I was at my mechanics for an air filter change I asked him to check my temperature in my car since it is almost 7yrs old and I never had a recharge..he said it was at 62 degrees and that I probably could use a lb of freon..so I let him do it and it needed less than a half of pound…I took the car home literally around the corner and today my cars ac is putting out hot air…what did they do to my ac…

    • BD Auto Pro on September 28, 2016 at 6:04 pm

      Denise,

      Thanks for your question about your Corolla. Your mechanic was correct that 62 degrees is a bit warm for air conditioned air. Hopefully, by adding more refrigerant your system simply got over filled and has shut off due to a high pressure switch being triggered. You can try checking your high pressure side pressure to see if it’s outside of the normal operating range to prove that is what’s happening.

      There are some other remotely possible things that happened like the fill valve got stuck open after he removed the AC machine, or that it was contaminated refrigerant. Hopefully if you take your vehicle back to that mechanic he will be able to check his work and determine what the problem is.

      Thanks again for your question!
      -BD Auto Pro

  13. TGreene on September 25, 2016 at 12:17 am

    i need to know why my ac blows warm air sometimes but not all the time. 2006 honda accord…its driving my wife crazy!! I DROVE the car the other day and it was very cold!! but later that night it started blowing warm air!! it has been doing that all summer. please help

    • BD Auto Pro on September 30, 2016 at 12:59 pm

      TGreene,

      Thanks for your question about your Honda Accord. Usually, with intermittent problems like you’re describing it is an electrical issue. You might have a bad connection for the signal wire to your compressor, a bad pressure or temperature sensor somewhere, or even a problem with your electric fans. Chasing down electrical issues can be a frustrating and time-consuming process, but if you’re willing to try it, start by reading our article about that here: https://gobdp.com/blog/diagnosing-electrical-problems/.

      Thanks again for your question!
      -BD Auto Pro

      • Dingbatqueen on June 7, 2021 at 4:12 pm

        1999 Plymouth Caravan here. The AC gradually got warmer over months. I’m thinking it might need Freon but I was told that I have to get it converted to some “new” AC system because they no linger fill older vehicles with the same refrigerant. Is that right? I’m a 64 year old lady who knows nothing about cars. How can I be sure that I’m not being taken advantage of? I make little on my retirement money and can’t afford to get ripped off. Thanks in advance, it’s truly wonderful how you help so many people on your site.

        • BlueDevil Pro on June 8, 2021 at 8:37 am

          Dingbatqueen-

          Thank you for asking about your Plymouth Caravan. It is true that older refrigerant, R-134a, is being phased out due to its contribution to global warming, and being replaced with R-1234yf. It’s always a good idea to get a second opinion in a situation like this. A good A/C specialist should at least be able to point you in the right direction.

          Thank you!

          -BDP

  14. Amanda on September 26, 2016 at 1:19 pm

    I have a 2011 ford fusion. I noticed issues with the ac when i would turn it on i can hear everything come on. Air would be blowing cold for 2 seconds and then it switches to hot air. And i mean hot like a blow dryer in your face. We thought it was the evap sensor so we pulled the dash and changed it. It worked last night. I got in my car today and it’s not working again. We checked the freon levels and it is normal. What are we missing? What could it be? Please help!

    • BD Auto Pro on September 30, 2016 at 1:17 pm

      Amanda,

      Thanks for your question about your 2011 Ford Fusion. Based on your description of how hot the air blowing out is, our guess is that you’ve actually got a problem with your ventilation system. There is a door in your ventilation system that directs the vent air either over the cooling coils or the heater core and it sounds like that is malfunctioning in your car and it’s switching to the “heat” position when you don’t want it to. This may be a problem with the servo controlling the door or with the computer module in your ventilation system. You can try checking the servo for operation but you may have to take your car to a Ford dealership to have them run a diagnostic on the ventilation module.

      Thanks for your question!
      -BD Auto Pro

  15. Marian Martinovic on October 7, 2016 at 10:35 am

    I have a Nissan xTrail T32
    when outside temp is below 10 degrees, I have my A/C on all the time, inside temp set to 20, the air out of vents is hot (feeling above 30 degrees) and during the 30 minutes drive does not change whatever the inside temp I set, either 17 or 25, wrong or normal based on sensors checking the inside temp, to me not as inside temp after 30 minutes ride is already high, quite hot so sensors should pick it up and adjust the air temperature blowing out of the vents as I have the inside temp set still to 20. What is the point of setting inside temp when it does whatever it does. It is automatic aircon but I do not use auto mode, I set it myself manually. Thanks for reply

    • BD Auto Pro on October 18, 2016 at 10:34 pm

      Marian,

      Thanks for your question about your Nissan xTrail. Based on your description it sounds like your automatic HVAC controls are malfunctioning. The problem could be coming from a bad sensor or a bad HVAC module. Unforutenetly, the only way to test those components is with a special computer from a Nissan technician so without replacing parts that may or may not be good, your best bet is to take your vehicle to the dealership.

      Thanks again for your question!
      -BD Auto Pro

  16. Kathy on January 3, 2017 at 6:30 pm

    I have a 2007 Honda Accord. My air conditioner blows out really hot air unless I turn the temperature setting to 66 or lower. Sometimes it blows hot out of one vent and cool out of the other side.

    • BD Auto Pro on January 19, 2017 at 5:47 pm

      Kathy,

      Thanks for your question about your 2007 Honda Accord. Since the AC does get cold at certain settings and you get different temperatures from different vents, it sounds like the problem is actually with your ventilation controls rather than your air conditioning system. There are a series of small motors that control flapper doors in your vent ducts that direct the air over the heater or cooling coils and it sounds like either the motor or door is broken causing the air to not go where you’re asking it to being heated or partially heated. These motors and doors are located behind your dashboard and take a good amount of work to get to so you may consider taking your vehicle to a mechanic to have them checked out.

      Thanks again for your question!
      -BD Auto Pro

    • George Korankye on March 5, 2022 at 4:12 pm

      I have a 2014 Ford Explorer and my A/C takes a long time to come on when the switch is turn on also it starts blowing hot air when the fan speed is reduced. I had it diagnosed and I was told it’s a sensor but we don’t know where the sensor is located can you please help if it’s truly the sensor and it’s so where can it be located

      • BlueDevil Pro on March 7, 2022 at 8:57 am

        George-

        Thank you for asking about your Ford Explorer. Based on your description, it sounds as though you are referring to the temp sensor, which would be located by the evaporator coils.

        Hope this helps!

        -BDP

  17. segun on January 5, 2017 at 10:01 pm

    I have a toyota corolla 2003. my car ac only works for about an hour and it starts blowing warm air thereafter, the first ac guy said it needed recharging which i did recharge, yet the problem persisted, another said there is a leakage in the evaporator,from much research i believe my air vent had accumulated a lot of leaves and other organic debris that probably have clogged my evaporator. in this case what can i do.

    • BlueDevil Pro on January 9, 2017 at 9:59 am

      Segun-

      Thank you for asking about your Toyota Corolla. Based on your description, we recommend taking your vehicle to an A/C specialist and having a A/C flush performed. They can dismantle the evaporator itself and flush it out specifically to get rid of any debris in the system.

      Thank you!

      -BDP

  18. Tom on March 23, 2017 at 4:16 am

    I filled my 97 Sentra with acpro it was very cold.couple days later ac blows warm what do you recommend.

    • BlueDevil Pro on March 23, 2017 at 9:16 am

      Tom-

      Do you happen to know where the leak is coming from? Are you losing a lot of refrigerant or is it more of a slight leak? Please contact our technical support line at 888-863-0426 so that we can get a better understanding of the vehicle’s condition and be able to make any appropriate recommendations.

      Thank you!

      -BDP

  19. Wilken on April 2, 2017 at 10:56 am

    I have a Nissan Altima 2011 Saturday morning my a/c in the car was working fine. Then in the afternoon all of a sudden it’s been blowing hot air. I check the coolant it’s full and there’s no leak. What you think might be the issue?

    • BlueDevil Pro on April 4, 2017 at 9:58 am

      Wilken-

      Thank you for asking about your Nissan Altima. Based on your description, there may be an issue with the condenser not functioning properly. If you are not noticing a loss of refrigerant, you may want to bring the vehicle in to an A/C specialist for a possible hard part replacement.

      Thank you!

      -BDP

  20. Elise on April 10, 2017 at 12:14 am

    Hello. I have a 01 Grand Am and the air has always worked. Even if my a/c was off and my control knob was on cool, cool air passed through the vents. I recently had my heater core replaced and my mechanic said he had to undo the a/c lines to replace the heater core. Im yet to refill the system with more freon because I am doubtful refilling the system will fix the problem. I have hot air blowing through my vents at all times. Even if the knob is in the off position. Did my mechanic do something wrong or do I need to refill the system for the problem to go away?

    • BlueDevil Pro on April 10, 2017 at 10:54 am

      Elise-

      Thank you for asking about your Pontiac Grand Am. Low refrigerant levels would explain the hot air you are experiencing. It is also possible, that due to the mechanic having to undo a/c lines to get to the heater core, that one of the lines was not put back on properly. You can refill the system and see if that corrects the issue. If not, there is probably a connection hose or line that is not properly connected.

      Thank you!

      -BDP

  21. RAMI on April 10, 2017 at 4:46 am

    i have nissan altima 2008 3.5L when i keep my car from night to morning to turn it on again the AC cold air will delay for like 5 to 10 minutes after that it will give less cold but it works the clutch work directly when you turn the AC on but the only thing is the delay of cold air, i wanted to hear from you before i change my compressor please can you give me more hints im in kuwait and next months we’ll get more than 47C temp:(:(

    • BlueDevil Pro on April 10, 2017 at 1:35 pm

      Rami-

      Thank you for asking about your Nissan Altima. Based on your description, it would be tough to say that a bad compressor is the reason for the delay you are experiencing. There could also be some kind of a restriction in the system causing the delay of the cold air. You can try flushing the A/C system first to see if that alleviates the situation.

      Thank you!

      -BDP

  22. Kennie on April 24, 2017 at 11:04 am

    Hi, I have a 2011 Toyota Camry and when I turn my a/c on it blows out hot air but then I’ll completely turn the car off and restart it and it will blow out cold air. This has happened 3 times so far this spring, do you know what the issue could possibly be?

    • BlueDevil Pro on April 24, 2017 at 4:17 pm

      Kennie-

      Thank you for asking about your Toyota Camry. A slow loss of refrigerant may be giving you the symptoms you’ve described. We recommend first checking the refrigerant level to ensure it is topped off to the proper level. If not, the Red Angel A/C Stop Leak & Conditioner (http://store.gobdp.com/a-c-stop-leak-aerosol-00222/) would be your best bet in sealing your A/C leak. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!

      -BDP

  23. Justin on May 9, 2017 at 11:19 pm

    Hi, I have a 2007 Ford Explorer and my ac is blowing warm air, added freon but still warm air, my compressor will run for about 4 seconds then shut off for about 4 seconds , then run for 4 seconds, will do this continuously until I turn vehicle off,the fans run, air filter is clean, radiator appears to be clean, what could my issue be?

    • BD Auto Pro on May 11, 2017 at 5:19 pm

      Justin,

      Thanks for your question about your 2007 Explorer. Based on your description of how the compressor functions it could be that your system is overfilled with refrigerant, that you’ve got a clog somewhere in your system or you’ve got a bad sensor somewhere. unfortunately, to find out which the problem is, you’ll have to check the high and low side pressures in your system. For more information about that, try checking out our article about AC troubleshooting here: http://goredangel.com/blog/ac-trouble-shooting-tips/.

      Thanks again for your question!
      -BD Auto Pro

  24. telisha on May 30, 2017 at 1:22 pm

    I have a 2006 chevy malbui my a/c is blowing out hot air I put 1 can and half can of freon in it it still blows hot air and then it blow cold air then goes back to blowing hot air again what could cause that,.

    • BlueDevil Pro on June 5, 2017 at 12:09 pm

      Telisha-

      Thank you for asking about your Chevy Malibu. Based on your description, it sounds like you are experiencing the symptoms of a refrigerant leak. We recommend using the Red Angel A/C Stop Leak to get your system back to normal functionality. You would want to have the system evacuated prior to adding the product and then you would be able to top it off with refrigerant after the leak was sealed.

      Thank you!

      -BDP

  25. Bob on June 13, 2017 at 10:31 am

    Have 1996 dodge dakota v8 had trans rebuilt now have warm air blowing from a.c.. filled with Freon and replaced main a.c. clutch fuxe blows hot air out better.any ideas

    • BD Auto Pro on June 15, 2017 at 5:40 pm

      Bob,

      Thanks for your question about your 1996 Dodge Dakota. Our first recommendation would be to check around the rear of the motor to see if any air conditioning lines may have been damaged during the maintenance. It would most likely be the lines going to and from the evaporator through the firewall. The other thing to check for would be loose electrical or vacuum connections that may be affecting the compressor getting the signal to turn on or the air blend door actuator from properly moving the air blend door to the “cool” setting. It is also possible that it is simply a coincidence that your air conditioning malfunction after the transmission rebuild so you should consider checking the high and low side pressures to see if they are abnormal.

      Thanks again for your question!
      -BD Auto Pro

  26. C. Johnson on June 26, 2017 at 5:48 am

    Have a 99 dodge van. The AC blows warm air, checked the refrigerant pressure read full/ normal range. I know that you can press the pin in to allow the fluid to come out, and visually see. Nothing happened. You can hear like air coming out. Is it possible that a line is clogged?

    • BlueDevil Pro on June 27, 2017 at 10:55 am

      C. Johnson-

      Thank you for asking about your Dodge Van. Based on your description, it is possible that a line or port has become restricted and is not allowing proper flow. We recommend bringing the vehicle to an A/C specialist for a system flush and see if that corrects the issue.

      Thank you!

      -BDP

  27. Vernon on June 26, 2017 at 12:28 pm

    I got 03 dodge 1500 I put new compressor new orifice new Condencer new sreader valve new concdencer fan still hot air could wrap core be clogged

    • BlueDevil Pro on June 27, 2017 at 10:50 am

      Vernon-

      Thank you for asking about your Dodge Ram 1500. Based on your description, it is possible the wrap core is clogged. We recommend bringing the vehicle to an A/C specialist for a system flush. This should get the a/c blowing cold again.

      Thank you!

      -BDP

  28. Rob Chisum on July 14, 2017 at 7:36 pm

    I have a 1999 Ford F150. When I first turn the a/c on it will blow cold. Once i start moving it goes hot. If i’m moving when I turn it on and don’t stop it will stay cold, (like driving on the interstate) but once I stop and then start moving again it goes hot.

    • BlueDevil Pro on July 17, 2017 at 11:01 am

      Rob-

      Thank you for asking about your Ford F-150. From the sounds of it, you may have a slow refrigerant leak, which is not allowing the system to continuously blow cold air. We recommend using the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-49496/) and then topping the system off with the proper amount of refrigerant.

      Thank you!

      -BDP

  29. tiger on July 16, 2017 at 10:24 am

    i got a 2006 Honda odyssey which blows hot air from only one port and the other ports blow cold air when the a/c is turned on. why does it do that…..kinda weird…

    • BlueDevil Pro on July 17, 2017 at 10:59 am

      Tiger-

      Thank you for asking about your Honda Odyssey. A loss of refrigerant could cause the issues you are experiencing. We recommend using the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-49496/ ) and then topping the system off with the proper amount of refrigerant. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!

      -BDP

  30. Guy Critelli on July 25, 2017 at 8:07 pm

    What would make the compressor run constantly and will it hurt the compressor to run like that it doesn’t cycle on and off is it the a.c. relay that is at fault. I had the system vacuum out and pressure text and passed but wouldn’t turn on until I jimmy rigged the relay it was converted from R12 to R134

    • BD Auto Pro on July 27, 2017 at 9:34 pm

      Guy,

      Thanks for your question about your AC Compressor. It’s difficult to tell what your problem might be based on the relay bypass you mentioned. If the pressures are as expected and your system is cooling properly, having your compressor constantly running shouldn’t damage the compressor or the system. Any time a system is converted from one refrigerant to another it also makes diagnosing problems difficult since the system is operating as it was originally designed.

      Thanks again for your question!
      -BD Auto Pro

  31. Tish Peterson on July 26, 2017 at 10:40 pm

    I have an 04 Honda CRV. I had the o8l changed the other day & was told that he thought i might hav a small leak somewhere. Then the a/c stopped working….blowing hot air. Does it need freon or is it the compressor???

    • BlueDevil Pro on July 27, 2017 at 10:04 am

      Tish-

      Thank you for asking about your Honda CRV. We recommend checking the refrigerant level to make sure it is reading at the proper level. If it appears low, use the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-aerosol-00222/) to help stop the loss of refrigerant.

      Thank you!

      -BDP

  32. Edie on July 30, 2017 at 1:32 pm

    Hi we have a 2003 Dodge Caravan and having issues with hot air blowing out when Air Conditioner is on. Freon and Fuse were checked and is ok. Freon is fully charged. Any suggestions?

    Thank you,
    Edie

    • BlueDevil Pro on August 3, 2017 at 10:46 am

      Edie-

      Thank you for asking about your Dodge Caravan. Based on your description, it is possible you are experiencing a slow refrigerant leak. We recommend using the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-aerosol-00222/) to help stop the loss of refrigerant and get the system back to normal functionality.

      Thank you!

      -BDP

  33. taytay on August 1, 2017 at 11:00 am

    Hi i have a nissan 2014 altima. when the car is running, it blows cold, when i am idle (stop sign, parked, very hot outside) it gets super hot. I’ve had freeon replaced and that would only work for a couple hours. I had an a/c person tell me my compressor may be failing, and some one else say its a leak, not sure what it could be

    • BlueDevil Pro on August 1, 2017 at 3:12 pm

      Taytay-

      Thank you for asking about your Nissan Altima. Based on your description, it sounds like you are experiencing a refrigerant leak, although it would be tough to say where the leak is coming from. We recommend using the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-aerosol-00222/) to help stop the loss of refrigerant and get the system back to normal functionality.

      Thank you!

      -BDP

  34. Ben T on August 15, 2017 at 4:23 am

    Hi I have a 03′ Toyota Corolla LE and the A/C does turn on. If you turn the dial to hot, the air is hot, but if you turn it to cold/cool it is just normal temperature. What could be the problem/ what could I do?

    • BlueDevil Pro on August 15, 2017 at 10:11 am

      Ben-

      Thank you for asking about your Toyota Corolla LE. Based on your description, it sounds like you are experiencing a slight refrigerant leak. We recommend using the Red Angel A/C Stop Leak (http://store.gobdp.com/a-c-stop-leak-aerosol-00222/) to help stop the loss of refrigerant and get the system back to normal functionality. Feel free to contact our technical support line at 888-863-0426 with any other questions.

      Thank you!

      -BDP

  35. Emeka on September 16, 2017 at 4:56 am

    i have a toyota matrix 2006, when you on the Ac, it will start cooling perfectly but after like 30Minutes, it will start blowing just air, if you notice it and off the compressor and on it again, it starts blowing cool again. also when you increase the speed of the fan from low to high or medium, it will blow just air and no cooling except only at low gauge. the technician whom i explained to told me that the compressor needed to be serviced which i agreed. after the servicing, it starts working fine but 2 days of usage, the compressor starts leaking oil from its oil seal (piston), i took it to the technician again and he said the oil seal got to be changed, he changed it, and it has started leaking oil again from same compressor after few days. and when ever this happens, the compressor will not be suppling much cooling again from the vents. he now said it is the Expansion valve that is pulling the oil seal. am confused. it wasnt pulling and leaking oil before but this started after the compressor servicing. should i change the compressor. thanks

    • BlueDevil Pro on September 18, 2017 at 9:37 am

      Emeka-

      Thank you for asking about your Toyota Matrix. Based on your description, we agree that the compressor should be replaced. After having it serviced and noticing a leak, your best option would be to replace the compressor.

      Thank you!

      -BDP

  36. David Dubois on September 22, 2017 at 6:50 am

    Hi, I have a Ford Explorer 1997 and after beeing on a rough 4wd track it only blows hot air. Even when the a/c is on off, hot air is blowing out of the vents. I noticed roughly one month before on a long drive on a warm day lots of ice around a hose connected to the drier and always lots of condense water dripping on stops, probably from the ice melting.

    • BlueDevil Pro on September 22, 2017 at 9:29 am

      David-

      Thank you for asking about your Ford Explorer. Based on your description, it is possible that the indoor unit’s evaporator coil is frozen solid and cold liquid refrigerant is flowing to the outside unit through the refrigerant line, which is likely why it’s covered in ice. We recommend turning off your AC and turning the fan setting to “On.” This will unfreeze the evaporator coil and prevent any damage to the compressor.

      Thank you!

      -BDP

      • David Dubois on September 23, 2017 at 6:57 am

        Thanks a lot for your reply. I researched a lot and also used your excellet a/c troubleshooting instruction. Altough it still doesnt work, I made a few discoveries.

        1a) When driving I turn off the a/c and fan, turn the blender from hot to cold, turn the fan and a/c back on it does blow cold air.
        1b) The above technique doesnt work when accelerating with full throttle.
        2a) Normally the air would only blow through the vents for the windscreen (also before I had the problem with no cold air). When i turn to the only fan option which doesnt use the a/c and have the fan on lowest strength, it blows out of the correct fans.
        2b) As soon as I use the trottle or set the fan to max strength, air only blows out of the windscreen vents.

        It seems to me as if the accumulators of the blender and vent doors somehow dont receive enough power or the doors might be stuck somehow?

        3a) When I start the vehicle and have the a/c on the cooldest setting and the fan on the weakest position, cold air is coming out of the vents. The tubes going from the evaporator to the drier and from there to the compressor are extremly cold.
        3b) When change the fan to the max and leave the a/c, the air from the vents isnt cold anymore, as well the tubes described above are not cold anymore. The compressor clutch starts to engage and disengage regularly.

        4) When I turn the motor off, I hear air or gas escaping with droping pressure until the sound dies. From the compressorr or maybe a leak?

        Thank you very much for your consideration.

        • BD Auto Pro on September 23, 2017 at 5:42 pm

          David,

          Thanks for your detailed description of what’s happening with your AC system. Based on point 3b it’s difficult to say that your problem is only with your ventilation system and it’s possible that your air conditioning system isn’t functioning at full capacity so it may be worth having the system’s pressures checked to make sure it’s functioning at full capacity so you can properly diagnose your ventilation system. All the games you have to play to get cold air to blow from the right vents does sound more like the flapper doors in your ventilation system are actually blocked or broken rather than the actuators being bad. It may be worth opening up your ventilation system to check the condition of the doors and look for blockage.

          Thanks again for your question!
          -BD Auto Pro

  37. John Clarkson on November 3, 2017 at 11:35 am

    Hello, I’m John and I have some problems with my Volkswagen Passat’s air conditioning system. I have had it checked by a Volkswagen dealership but they say that everything is fine.

    1) First, my Passat is blowing warm-to-slightly cool air even when the A/C is set to the lowest temperature with maximum fan speed when it is hot outside, and it leaves me sweating inside the car. But it works fine and blows normal cold air when it is cool outside. What could be the problem?

    2) Secondly, my Passat is a Right-Hand Drive (Asian) variant, and the vents (each at both sides, and two at middle) are not working equally. The vents on the left and middle-left are blowing warm air whenever the A/C is switched on, and they requires a very long time to blow slightly cool air when it is hot outside. Even when it cool outside, the left vent tend to blow warmer air and takes longer time to finally blow cold air. The vents on the right and middle-right always blow cooler air and takes shorter time to do that, but they still blow not-cold-enough air during hot weather. What is the problem there?

    3) Thirdly, this might not be an actual problem, but I have observed that whenever my A/C is turned on, there is a high pitched sound, it sounds like highly-pressurised air is passing through the dashboard, and the sound slowly fades off after a moment.

    Here are my 3 problems regarding my 2014 Volkswagen Passat, I would really appreciate your kind assistance. Thanks.

    • BD Auto Pro on November 7, 2017 at 11:15 pm

      John,

      Thanks for your question about your Volkswagen Passat. In our experience, if you’re having multiple symptoms they can often be related back to a single problem. Since you mentioned different temperatures coming from each vent, out guess is that you’ve got a problem with your ventilation system, most likely a blockage in the air box causing the air blend door to not close fully and the air flow to be disrupted to the vents. Try removing your air box and checking for debris or damage to the flapper door. The hissing sound you mentioned could be the normal sound of refrigerant flowing through your evaporator or it could indicate that you’ve got a clog in the system there. You can try checking the high-pressure side of your air conditioning system to see if you can find evidence of a clog.

      Thanks again for your question!
      -BD Auto Pro

      • Marco on July 10, 2019 at 11:19 pm

        Hello I have a 2007 Chevy Tahoe and my ac has always worked great but recently I started having problems with the battery and the ac only blows hot air out the bottom now,,,, I’ve put a new battery in the truck and it continues to do the same thing,,,, any advise would be greatly appreciated….. thank you

        • BD Auto Pro on July 10, 2019 at 11:34 pm

          Marco,

          Thanks for your question about your 2007 Chevy Tahoe. If you’ve got an automatic climate control system in your Tahoe it’s possible that the dead battery caused it to malfunction and shutdown. Now that you have a new battery installed you may need to reset the HVAC module to get it back to working like normal. Any local shop with a good scan tool should be able to do that for you. The other possibility is that the mode door actuator has failed while the mode door was in the “foot” position and replacing the actuator should get things working correctly. A good scan tool should also be able to test this actuator and tell you if that is the problem.

          Thanks again for your question!
          -BD Auto Pro

  38. jacob humsilton on November 3, 2017 at 12:27 pm

    It’s a 2011 Altima 2.5 and reading are 33 and 160 on a 80 degree day ? Blows 80% cold air , low line sweats .. when I unplug the high plug on the car side it’s under lots of pressure ? It shoots out some freon is that normal ?

    • BD Auto Pro on November 7, 2017 at 11:17 pm

      Jacob,

      Thanks for your question about your Nissan Altima. It is not normal for the refrigerant to come out of the high-pressure port of your air conditioning system. It sounds like the high-pressure port valve may have failed in your car and should be replaced.

      Thanks again for your question!
      -BD Auto Pro

  39. Pat D on February 22, 2018 at 5:50 pm

    I have a chrsyler 200 2011 v6. The AC blows okay and just okay. Its definitely not hot air and if i had to guess i’d say its blowing low 70s/high 60s but kind of weak. Its not as frigid cold as it used to be. I can sometimes see ghostly vapors blowing if i look at a vent from an odd angle in the sunlight. Any ideas or clues?

    • BD Auto Pro on February 22, 2018 at 6:25 pm

      Pat,

      Thanks for your question about your Chrysler 200. It’s possible that you’ve got a small refrigerant leak in your evaporator. That would lower the refrigerant levels in your air conditioning system causing it to be inefficient and not cool as well and could be the vapors you’re seeing from your vents. If you find this to be the case, use Red Angel A/C Stop Leak to seal up the leak.

      The other possibility is that you’ve got a clogged cabin air filter or your evaporator is icing over reducing air flow causing the air to warm up before it gets out of the vents and would add moisture to the air causing the vapors you’re seeing. If this is the case, try changing your cabin air filter and checking the high side pressure in your air conditioning system.

      Thanks again for your question!
      -BD Auto Pro

  40. Derrick on May 11, 2018 at 2:43 pm

    I have a 2000 accord v6, the AC seems to run fine all day when temperatures are at 80 degrees or lower. When the temperature reaches above 85 degrees or higher, the AC will runs cold for 5 minutes then go hot. If I let the car sir for about an hour, the AC will run cold again for about 5 minutes but then turn hot again. Had the system flushed an refill but still have the same problem. Mechanic say I should change the whole system but it is too expensive. Any help in the right direction will be appreciated. Thanks

    • BD Auto Pro on May 15, 2018 at 9:35 am

      Derrick,

      Thanks for your question about your 2000 Accord. Often times if things work properly in your AC until the temperatures get too hot it is either due to a clog in your system or because your system is overfilled. You could try checking both the high and low pressures on a very hot day and see if the pressures indicate the system is overfilled. If that is the case, your mechanic would be able to rectify the problem by recovery and refilling the system again with the correct amount of refrigerant. If the system has the correct amount of refrigerant but there is a clog, it could cause an extremely high pressure on a hot day and similarly trip the system off due to the overpressure. If your system has multiple high-pressure test ports you may be able to locate the clog but if it doesn’t your mechanic is correct that you would have to replace multiple components basically guessing at where the clog is.

      Thanks again for your question!
      -BD Auto Pro

  41. Shelly Sarfate on June 6, 2018 at 7:07 pm

    I had the compressor replaced in my 06 CRV last September, $1500. Now my a/c works, but when I’m at an idle it turns warm and if it idles for too long, it starts to overheat. Any ideas?

    • BlueDevil Pro on June 7, 2018 at 9:21 am

      Shelly-

      Thank you for asking about your Honda CRV. Based on your description, it is possible that a faulty condenser fan is causing the air to blow warm at idle, and could also explain why the vehicle starts to overheat. When you’re driving, the fan is cooling the refrigerant inside the condenser, and at idle, it isn’t getting sufficient airflow for cooling. You can check the fans and see if they’re turning on and doing their normal cycle and check that the compressor clutch is coming on.

      Hope this helps!

      -BDP

  42. Diamond M Fernandez on July 2, 2018 at 6:41 pm

    I have a 2014 Mustang and it will first blow cold air but then 5-10 minutes into driving it will release a wierd A/C smell, then start blowing warm/hot air.

    • BlueDevil Pro on July 3, 2018 at 9:05 am

      Diamond-

      Thank you for asking about your Ford Mustang. If you are smelling an A/C smell, there is a good chance you are experiencing a refrigerant leak. We recommend using the Red Angel A/C Stop Leak (https://store.gobdp.com/a-c-stop-leak-aerosol-00222/) to help stop the loss of refrigerant and get the A/C system back to normal functionality.

      Thank you!

      -BDP

  43. Mike Dvorak on July 5, 2018 at 7:32 am

    2009 Honda Civic Si. When I first start it up, it blows cold and if I just sit there it blows cold for at least 20 mins(that was how long i just let it run so could be indefinite). When I start driving, after 5 to 10 mins it blows Luke warm. I have replaced relays and made sure there was enough refrigerant in the system. Both fans were running at idle. Any ideas would be appreciated.

    • BD Auto Pro on July 9, 2018 at 9:50 pm

      Mike,

      Thanks for your question about your 2009 Honda Civic. It’s possible that your air conditioning system is overfilled and when your engine is at a higher RPM the pressure gets too high and the system trips off on overpressure. A clog somewhere in your system could also cause a similar problem. To check for this you would have to use a set of mechanic’s AC gauges to read the high-pressure side and do so with the engine above idle speed.

      Thanks again for your question!
      -BD Auto Pro

  44. RICHARD DEVISSER on July 13, 2018 at 12:44 pm

    2009 Uplander repaired line to rear and took it in had it vacuumed and filled – worked good at first but after a month no a/c.
    Have tried to fill in case it leaked but pressure seems good – compressor cycles, condenser fan cycles like normal, but only blows hot air (front or rear).
    Any ideas?

    • BlueDevil Pro on July 13, 2018 at 2:45 pm

      Richard-

      Thank you for asking about your Chevrolet Uplander. The fact that the A/C ran well for a month after the repair was performed sounds as though you are experiencing a slow refrigerant leak. Based on your description, we recommend using the Red Angel A/C Stop Leak. This will stop the loss of refrigerant and return the A/C to normal functionality.

      Thank you!

      -BDP

  45. Robin K on July 25, 2018 at 4:59 pm

    My 2013 VW Passat blows hot air (like a heater) most mornings. It seems to happen when the car has been sitting for some time regardless of the temperature outside. After about five minutes, it blows cooler, but not as cold as it used to. I also smell a moist smell in the vehicle and feel that the cool air has moisture to it if that makes sense. Any advice?