A/C Compressor Clutch Relay

A/C clutch relay is controlled by PCM. When A/C mode is selected and PCM receives A/C request signal from evaporator switch, PCM will cycle clutch on and off through A/C clutch relay. When this relay is energized during engine operation, PCM will determine correct engine idle speed through IAC motor.

When PCM senses low idle speed or wide open throttle through TP sensor, PCM will de-energize A/C clutch relay, preventing A/C operation. PCM also de-energizes relay if engine coolant temperature is more than 257°F (125°C). On Cherokee equipped with A/C, whenever A/C compressor clutch is energized, PCM will also energize auxiliary radiator (cooling) fan relay. This occurs regardless of engine coolant temperature.