Compressor Clutch: Description and Operation

The magnetic clutch transmits the engine power to the compressor when the A/C button is depressed. The clutch assembly consists of a drive plate, pulley and field coil. The drive plate is splined to the compressor shaft. The pulley and bearing assembly is pressed on the compressor hub, and the field coil is mounted to the compressor body. When current flows through the field coil, the drive plate is pulled into the pulley by electromagnetic force.

When the field coil is not energized the drive plate separates from the pulley and the compressor stops. A diode is used to protect electrical circuits from voltage spikes. The diode is located in the underhood junction block.