When ever the car stops at a traffic light or stop sign, the air compressor cycles rapidly and the cool air turns warm. I was told the cooling fan was not coming on, but the other day the fan was cycling and the cool air stayed cool. My question is what controls the cooling fan operation? It seems the high pressure switch is working correctly and the fan motor is working. As long as I’m driving the air is cool.
If the AC compressor clutch is disengaging then check for a bad wire connection to the clutch. There may also be an issue with the system pressure causing the trouble.
The PCM controls the cooling fan based on inputs from the A/C pressure transducer, coolant temperature sensor and transmission fluid temperature sensor. Using a scan tool you can monitor the A/C pressure transducer voltage/pressure and may be able to identify the problem. Removing the A/C pressure transducer may get you a face full of refrigerant so I recommend taking your vehicle to a shop.