Why is My Car AC Blowing Hot Air?

car ac blowing hot airJumping into your car after a sunny spring day can be an unwelcome surprise.  The windows and cabin of your vehicle act a lot like a greenhouse when it’s left in direct sunlight.  The sun’s energy can enter through your windows or be absorbed by the metal roof but has no way to escape.  This heat is trapped and can cause the interior of your vehicle to get extremely hot on sunny days.  You can help mitigate this effect by tinting your windows, choosing a light color paint or using a windshield sunshade but even these are not solutions, they just slightly lessen the burn marks on the back of your legs from your hot leather seats.

When you’ve paid a premium for air conditioning in your car you’re ready to be comfortable when you hop in.  Of course, it takes a few seconds for the air to get cool, but what if you’ve waited a minute or so and you’ve still got your car air conditioner blowing hot air in your face?  Before you zip down to the dealership and pay for a vehicle inspection to figure out why your car’s air conditioner is not blowing cold air, try checking a few common easy to fix problems listed below.

“Why is my AC blowing hot air?” Check These Common Causes:

  • Blocked condenser
  • Broken cooling fans
  • Broken condenser
  • Low refrigerant due to a leak
  • Electrical faults

The condenser in your air condition system looks a lot like a radiator and is mounted at the front of your vehicle.  It is used to cool the hot compressed refrigerant back to ambient temperature as it comes from your compressor and uses the air your car is traveling through to do that.  If this isn’t accomplished, the refrigerant will still be hot when it travels through the expansion valve.  If this is the case the hot refrigerant will only be cooled back down to ambient temperature so your AC won’t work.  Since the condenser is at the front of your vehicle, it has the opportunity to get clogged by all kinds of road debris from leaves to plastic bags or anything else you might drive into.  A quick visual inspection of the condenser through your grill can help you tell if it’s blocked.

Like having a blocked condenser, having broken cooling fans can cause a lack of cooling at your condenser and could cause your car AC blowing hot air.  The fans could actually be broken, like a burnt out motor, bad mount a chipped fan blade, or they could simply have an electrical problem like a blown fuse or burnt out relay.

Since your condenser is at the front of your vehicle it is also subject to less kind road debris like rocks, sticks or other hard objects that may puncture it.  If the puncture is large and easy to see, replacement is likely your best bet.  If you cannot see the puncture, consider adding UV dye to your air conditioning system to identify the puncture point, or simply add Red Angel Air Conditioning Stop Leak to your air conditioning system to quickly and permanently seal the leak.

Similarly, you may have low refrigerant due to other causes like loose connections, old hoses or the simple escape of refrigerant over time.  These small leaks can cause your air conditioning system to stop blowing cold air.  Before you recharge your air conditioning system, add Red Angel A/C Stop Leak to ensure your system is properly sealed and will hold your new refrigerant.

Lastly, you could have an electrical problem with your system.  Like broken condenser fans and electrical fault can cause a normally working system to stop working simply due to a bad connection or faulty sensor.  Electrical problems can include a faulty signal from your ventilation system caused by a broken wire or bad module, bad sensors tripping off your system or even a sensor in your vehicle’s motor that is causing the system to shut off inadvertently.  For more information on tracking down electrical issues like this, read our article on diagnosing electrical problems.

Red Angel AC Stop Leak & Conditioner





A simple visual inspection and a can of Red Angel A/C Stop Leak is all you need to solve many of the common easy to fix problems with your air conditioning system!  Stop by one of our partnering auto parts stores today to pick up a can of Red Angel A/C Stop Leak & Conditioner today!

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto Parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributor
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  • Bond Auto Parts stores
  • Tidewater Fleet Supply
  • Bumper to Bumper Auto Parts
  • Any Part Auto Parts
  • Consumer Auto Parts

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car_ac_blowing_hot_air.jpg – By dnberty – Licensed by Getty Images – Original Link