When you get into a hot car in the summer, the first thing you want to do is blast the A/C. It may take a while for the air to get cool, but if your AC continues to blow hot air only, there may be a problem. Driving in the heat can become a miserable and even dangerous task if you don’t have a working A/C. Read below to get reasons why your car AC blowing hot air only.

Lost charge of refrigerant — To see if your car has lost the charge of the refrigerant, you should use an A/C pressure gauge. In the engine, you should connect to the high side of the service port in the high-pressure hose that runs between the compressor and the condenser. This will tell you if there pressure in the system. If there is not enough pressure, your air conditioning may be out or refrigerant or it may have leaked out. You should vacuum out the air and recharge the system with refrigerant. Any extra air will reduce cooling and make the compressor very noisy.

Compressor isn’t engaging — Another potential issue may be with the compressor.  You should see if it is properly engaged when you turn on the air conditioning. If it does, the problem is inside the HVAC unit itself.  If it doesn’t then try to jump the compressor clutch wire directly with the battery.  If this works, then the problem is with the A/C compressor relay or pressure switch. If it doesn’t engage, then the clutch is broken.

Obstruction in system — If both the refrigerant and compressor are working, there may be an obstruction somewhere in the system. The orifice tube is located in the high-pressure hose. A blockage here will stop the refrigerant from getting into the evaporator and circulating. If this tube is blocked, then the high side pressure reading will be lower than normal. You should try to get in and get rid of the obstruction.

Getting Help

If you cannot seem to figure out what the problem is with your air conditioner, you should seek professional help. Use TalkLocal to be put in contact with reliable local businesses almost immediately.  Simply input your problem and availability and TalkLocal will do the rest. Within minutes your should be connected with a qualified HVAC company.

This entry was originally posted on Tuesday, November 27th, 2012 at 10:00 am and is filed under Auto Repair. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.