Grand Cherokee 2WD Limited V8-4.7L (2002)
Compressor Clutch: Description and Operation
Fig.4 Compressor Clutch - Typical
The compressor clutch assembly consists of a stationary electromagnetic coil, a hub bearing and pulley assembly, and a clutch plate. The electromagnetic
coil unit and the hub bearing and pulley 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 bolt.
The compressor clutch components provide the means to engage and disengage the compressor from the engine serpentine accessory drive belt. 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.
The compressor clutch engagement is controlled by several components: the a/c switch on the a/c heater control panel, the Automatic Zone Control
(AZC) control module (if the vehicle is so equipped), the evaporator probe, the a/c high pressure transducer, the a/c compressor clutch relay the Body
Control Module (BCM) and the Powertrain Control Module (PCM). The PCM may delay compressor clutch engagement for up to thirty seconds.
Refer to Electronic Control Modules for more information on the PCM controls.
