Why is My Car's Air Conditioning Blowing Warm Air?

Sun Devil Auto Expert, published on 07/11/2016

Your air conditioner is great—when it’s working well. When it isn’t, driving in your car can be uncomfortable, especially on hot summer days. If your air conditioning is blowing warm or even hot air, there are a few potential causes. Here are some of the most common reasons.

Electrical Issues

First of all, your electrical system might be having problems. The wiring, switches, fuses, relays, and other components of the electrical system carry power to the AC unit and are designed to shut down in the event of even one part failing. While this prevents serious trouble such as electrical fires, it also means that a single blown fuse can cause the entire air conditioner to stop working. Some of the most common causes of AC failure are rooted in electronics.

Change The Cabin Air Filter

While not all vehicles are equipped with cabin air filters, those that do have them need a clean, unobstructed surface to allow air to move through freely. Cabin air filters can capture dust, bugs, leaves, and other various types of debris. A dirty air filter can certainly impede your air conditioner’s ability to cool and after time could cause unnecessary strain on the entire system.

Compressor Failure

Another common potential reason is that your compressor has failed. The compressor is in charge of circulating refrigerant, moving it through a series of stages that result in heat being transferred away from your car so that cool air moves in. Since it’s one of the most important components of an AC unit, compressor failure can cause the entire system to stop working.

Refrigerant Leak

It’s also possible that the problem could be caused by the refrigerant itself—or at least, the lack of refrigerant. If your system has a leak, it could be causing the unit to blow warm air, since there isn’t enough refrigerant in the system to cool things down. Unfortunately, refrigerant leaks can be hard to detect because refrigerant becomes an invisible gas once it leaves your AC system. Auto shop professionals use specialized tools such as UV detectors to figure out whether or not your system has sprung a leak.

Leaking or Obstructed Condenser

Finally, it’s common for condensers to get clogged with the remains of the refrigerant and other particle deposits. Also, since the condenser is located at the front of the vehicle, it is more vulnerable to debris from the road such as leaves, plastic bags, or rocks and sticks that could cause punctures.  The condenser is a network of pipes resembling a radiator and is used to cool down hot refrigerant as it cycles through the system. However, if it fails to do this or does it inefficiently, the refrigerant will remain warm and won’t be able to cool the air past the ambient temperature. If this condenser breaks or is otherwise damaged, your air conditioner will blow warm air.

Get Help

To keep cool and comfortable this summer, Setup an Appointment to have your vehicle inspected by our professional air conditioning specialists.