Compressor Clutch Relay: Description and Operation
AIR CONDITIONING CLUTCH RELAY-PCM OUTPUTThe air conditioning clutch relay is located in the PDC. The inside top of the PDC cover has a label showing relay and fuse location.
The PCM controls the air conditioning clutch relay ground circuit. The A/C clutch relay coil side contains a 10 amp fuse between the buss bar in the Power Distribution Center (PDC) and the relay. The power side of this relay is fused with a 40 amp fuse. When the PCM receives an air conditioning input, it grounds the A/C compressor clutch relay and the radiator fan relay.
When the PCM senses low idle speeds or wide open throttle through the throttle position sensor, it removes the ground for the A/C compressor clutch relay. When the relay de-energizes, the contacts open preventing air conditioning clutch engagement. Also, if the PCM senses a part throttle launch condition, it disables the A/C compressor clutch for several seconds.