Why is My Air Conditioning Not Working?

This time of year, your air conditioning becomes more and more important every day. As the temperatures rise, the days get longer, and the sun gets hotter, it is more and more important to have a properly functioning air condition system to keep your ride comfortable and convenient. Just about every car today comes standard with air conditioning to the point where it has become more of a necessity than a luxury. Even so, air conditioning systems in production vehicles today have remained largely unchanged since they started being installed in the 1940’s 50’s.

All air conditioning systems use a compressor as the motive force behind the system, a condenser to cool the compressed refrigerant, an expansion valve or orifice tube to create the cooling effect and an evaporator to transfer the chill from the refrigerant into the air in your vehicle. The biggest difference in air conditioning systems from the 50s and of today is the actual refrigerant. Many different refrigerants have been used, some early Cadillac systems even used ammonia as the refrigerant. Today’s refrigerants are synthesized compounds specials formulated to work at the temperatures and pressures used in vehicles and make for a very efficient air conditioning system. R-12 was popular until the 90s when the Clean Air Act made it illegal to produce R-12 as it is a hazard to the environment, so now R-134a is standard.

If you’ve found your air conditioning not working this summer then it is likely due to one of a few simple problems.

Your compressor isn’t raising the pressure enough
Your expansion valve isn’t reducing the pressure enough
There is no air flow over your condenser
There is no air flow over the evaporator
There is a clog in the system
You don’t have enough refrigerant for the system to operate properly.

Your air conditioning system has a high pressure and a low pressure side. The high pressure side starts after the compressor and includes the condenser and the connecting hoses. The low pressure side starts at the expansion valve and includes the evaporator, dryer and those connecting hoses. If the pressure is too high or too low on either side it can cause your system to malfunction or at least not function at its highest capacity. You can check the pressures in your AC system using a set of mechanic’s AC gauges available at most auto parts stores. Each vehicle is a little bit different, so you will have to check your maintenance manual for the correct operating pressures for your particular system.

The condenser and evaporator are like radiators in that their job is to transfer heat between the air flowing over them and the fluid running inside of them. The condenser on the front of your car transfers heat out of the refrigerant and into the air blowing over it. The evaporator inside your car transfers heat out of the air and into the refrigerant running through it effectively cooling the air and making you comfortable. If either of these components have blocked air flow it could causing your air conditioning to not be working. Your condenser is at the very front of your car so check around it for leaves, dirt or anything else can be blocking air flow. Also, check to make sure cooling fans turn on when you turn on your AC button. If these fans don’t come on, you may not have enough air flow over your condenser to make the system work properly. For the evaporator, check your cabin air filter for debris and dirt to make sure it is getting the proper flow. Also, check to make sure your ventilation fan is operating properly.

If you have an air conditioner not working because of a clog, you will discover that with your AC gauges. A clog will result in an abnormally high pressure on the high pressure side of your system. Clogs usually occur in the condenser due to the small tubes, the orifice tube, or the dryer. Air Conditioning systems cannot easily be flushed so replacing the clogged component is the best way to solve the problem.

The most common cause of air conditioning failures is due to a lack of refrigerant. Due to the high operating pressures of the system and the characteristics of R-134a, it is not difficult for it to escape even through small leaks. If you simply add more refrigerant it will again leak out of the system soon causing a failure. Before you recharge your air conditioning system, add BlueDevil Red Angel AC Stop Leak to seal any leaks. BlueDevil Red Angel AC Stop leak is a leak stop that contains no particulates or anything else that could clog your system. At the leak point, the temperature differential will cause BlueDevil Red Angel AC Stop Leak to form a chemical weld sealing your leak and keeping your air condition working properly and you comfortable.