A/C Turns On/Off By Itself

[Boosted98gsx]

Driving around town or on the highway with my A/C on, it will blow cold for about a minute then blow warm. Knob is all the way in the blue, recirc/ambient doesn't matter, and the A/C light stays lit the entire time.

I had my A/C system checked out at satan a year ago, i have no freon leaks.

 

[4BangR-x]

Sounds like the compressor is about dead.

 

[Old Mitsu Tech]

A year ago, a day ago, doesn't matter. You can develop a problem at any time. Put some gauges on it and give us a reading. If your condenser fan has quit, you could be developing high head pressure which would do that. Get some actual readings. That way we can have something to go on. See if the lo pressure line is cold, wet and sweaty. You could have a bad cycling switch or anything. See with a test light while it's kicking in and out if the voltage to the compressor is also kicking in and out. If it is, then just follow it back to the source. A good schematic is vital at this point. Get one.

 

[Defiant]

Sounds like low refrigerant level in the system.

 

[Lenn]

From past personal experience, the thermo-switch inside the compressor is probably shorted out and allowing the compressor to overheat and shut off. The only way I know of to fix that is to replace the compressor. Maybe an AC shop can rebuild it but I dont know. If it blows cold at all that means that there is enough refrigerant to get the pressure switches to activate the compressor and make cold air but the compressor may be overheating.