Compressor Clutch Coil: Description and Operation

A/C Compressor Clutch:

The A/C compressor clutch assembly consists of a stationary electromagnetic A/C clutch field coil, a pulley bearing and pulley assembly, and a clutch plate. These components provide the means to engage and disengage the A/C compressor from the engine accessory drive belt.

The A/C clutch field coil and the pulley bearing and pulley assembly are both retained on the nose of the A/C compressor with snap rings. The clutch plate is splined to the compressor shaft and secured with a bolt.

When the clutch coil is energized, it magnetically draws the clutch 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 clutch and coil are the only serviced parts on the compressor.

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

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