GM Service Manual Online
For 1990-2009 cars only

Object Number: 345605  Size: MF
(1)Pressure Plate
(2)Key
(3)Snap Ring
(4)Compressor Clutch Pulley
(5)Compressor Clutch Coil
(6)Oil Felt Ring
(7)Seal
(8)Compressor

The air conditioning (A/C) system compressor is driven by a belt from the engine crankshaft through the compressor clutch pulley.

The compressor pulley rotates freely, without turning the compressor drive shaft until an electromagnetic clutch coil is energized. When voltage is applied in order to energize the clutch coil, the pressure plate is drawn rearward toward the pulley. The magnetic field locks the pressure plate and the pulley together as 1 unit in order to rotate the compressor drive shaft.

The A/C compressor performs 2 main functions:

    • The compressor compresses low pressure refrigerant vapor from the evaporator into a high pressure, high temperature vapor.
    • The compressor pumps the refrigerant and the refrigerant oil throughout the A/C system.

The clutch coil is energized by the A/C compressor control module. Refer to Air Conditioning (A/C) Compressor Control Module Description .

The following compressor components can be replaced:

    • The clutch coil
    • The clutch pulley
    • The drive shaft seal
    • The pressure plate
    • The pressure relief valve

Replace the compressor as a unit if any internal part of the compressor assembly malfunctions or wears out. Refer to Air Conditioning Compressor Replacement .