Why is my AC Blowing Hot Air?

ac blowing hot airThere are lots of reasons why you could have the AC blowing hot air in your car.  The air conditioning system in your car is a complex system that works in a very difficult environment.  Any number of factors could cause hot air to be blowing from your vents, but what makes answering this question even more complex is that diagnosing your ventilation or air conditioning system can often require special tools or long procedures to get a definitive answer.

For example, one reason for the hot air is that your ventilation system is malfunctioning.  If this were the case, then your air conditioning system would be creating the cooling effect necessary to cool the air in the cabin of your vehicle, but your ventilation system isn’t properly directing the air over the cooling coils then out of the vents in your car.  If you suspected this problem in your car, the only way to positively identify this as the problem would be to take apart a significant amount of your ventilation system to test the servo motors and check the flapper doors for damage or jamming.  This process could take a professional mechanic with the correct tools 6-8 hours which means it could take a weekend mechanic with limited tools up to twice that!

Similarly, your air conditioning system doesn’t have any self-diagnostic system like your car’s engine computer that can tell you if a certain sensor has failed, or what the engine conditions were when a particular fault happened.  Instead, each sensor must be tested manually and the normal readings must be found in a comprehensive vehicle repair manual.  To learn what’s actually going with your AC blowing hot air, you need to use a set of mechanical AC gauges that measure pressures in different areas of your system to help you find out where the abnormalities are.

Even though all these things make it very difficult for a vehicle owner to understand why their AC is blowing hot air, there are some things you can check easily to help narrow down what the problem might be.

For example, before you go tearing apart the ventilation system in your car, it can be smart to check the AC lines under the hood.  If you’ve got hot air blowing out of your vents, but the AC lines under the hood get cold to the touch quickly after turning on the air conditioning, then you most likely do have a problem with your air blend door or another part of your air conditioning system.

Similarly, you can check your compressor operation by having a friend turn on the air conditioning while you are watching the AC compressor pulley.  If you can see the clutch engage and the pulley start spinning you know you’ve at least got a little refrigerant in your system and you’ve either got a clog, a slow leak or an internal failure in your compressor.  If the compressor doesn’t cycle at all when the AC is turned on, you may have a system that is completely empty of refrigerant, a bad sensor somewhere, a seized compressor or an overfilled system.

Performing these two checks are one of the quickest ways to get an idea of what might be wrong with your air conditioning system.  To gain much more information than that, you’ve got dig into your ventilation system, or get the pressures checked in your air conditioning system.

Once you get your pressures checked, if you discover a leak, you should consider using Red Angel A/C Stop Leak to seal to leak and avoid costly equipment replacement.  Red Angel A/C Stop Leak is a fast acting stop leak agent that will seal the small leaks in your system without having to remove any equipment.

For more information about Red Angel A/C Stop Leak, click on the banner below!
Red Angel AC Stop Leak & Conditioner






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

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