Problem with air conditioner
 

On several occasions this summer, my air conditioner started blowing warm air. Sometimes this would happen after a short 15 or 20 minute drive, and at other times after an hour or two.It seemed like really hot days were a factor. The car is currently at the dealership, but after talking to the service department, I don't think they will be able to get the car to blow warm air and come up with an answer. There are no leaks in the system and the freon is properly charged. Can anyone tell me what I should be looking for.

HIGH COOLANT TEMPS. ABOVE 110C WILL CAUSE COMPRESSOR CUT-OUT.
EVAP. TEMPS BELOW 2C WILL ALSO CUT OUT COMP.
YOUR CAR IS EQUIPPED WIYH ONBOARD SELF DIAGNOSTICS,ANY TECH. WITH THE RIGHT TEST EQUIPMENT SHOULD BE ABLE TO PULL UP CODES.
MF

You did not say exactly what model your car is. It may very well be equipped with a belt slippage sensor on the compressor. If so, an oily or loose belt can cause your problem.

Good luck,

wish to second larry b's. opinion. check belt tension, belt tensioner and damper. replace if necessry.

another area to look at is any slippage of the clutch. again
if oily, clutch will not engage. the fix for this problem
is a can of engine degreaser. spray and rinse clutch area.

also, check sensor on top of compressor. there are two
screws on it. tighten these if necessary. good luck.

you need your a/c working to dehumidify the cabin air
this winter. otherwise, all windows will fog up. this
is a safety issue, especially if driving in the freeway.