Compressor Clutch Coil: Description and Operation

Compressor Clutch - Typical:

The compressor dutch assembly consists of a stationary electromagnetic coil, a rotor bearing and rotor assembly, and a clutch plate. The electromagnetic coil unit and the rotor bearing and rotor assembly are each retained on the nose of the compressor front housing with snap rings. The clutch plate is keyed to the compressor shaft and secured with a nut. These components provide the means to engage and disengage the compressor from the engine serpentine accessory drive belt.

When the dutch coil is energized, it magnetically draws the dutch into contact with the pulley and drives the compressor shaft. When the coil is not energized, the pulley freewheels on the clutch hub bearing, which is part of the pulley. The compressor dutch and coil are the only serviced parts on the compressor.

The compressor clutch engagement is controlled by the following components:
- A/C heater mode control switch
- A/C compressor clutch relay
- A/C high pressure switch
- A/C low pressure switch
- Powertrain Control Module (PCM)

The PCM may delay compressor clutch engagement for up to thirty seconds.