Before servicing the vehicle, refer to the Precautions Section.
NOTEDisconnecting the negative battery cable on some vehicles may interfere with the functions of the on-board computer systems and may require the computer to undergo a relearning process, once the negative battery cable is reconnected.
NOTEIf working near and/or around the SRS system and components, be sure to properly disable the SRS system. See disarming/arming the SRS system.
NOTEFor vehicles equipped with OnStar (RPO UE1), with battery backup, the backup battery is a redundant power supply to allow limited ONStar functionality in the event of a main battery power disruption to the OnStar module (VCIM). Do not disconnect the main vehicle battery or remove the OnStar fuse with the ignition key in any position other than OFF. Retained accessory power should be allowed to time out or be disabled by opening the driver-s side door before disconnecting power. Disconnecting power to the module in any way while the ignition is ON or with the retained accessory power activated may cause activation of the OnStar backup battery system and will discharge and permanently damage the backup battery. Once the backup battery is activated it will stay on until it has completely discharged. The backup battery is not rechargeable and once it is activated, it must be replaced.
- Disconnect the negative battery cable.
- Properly discharge the air conditioning system.
- Drain the cooling system, as required. Be sure to properly dispose of used coolant.
- If equipped with manual cooling fan, remove the upper radiator shroud and upper radiator hose and pipe.
- Disconnect and plug the freon lines.
- Raise and safely support the vehicle, as necessary.
- Remove the drive belt. Remove the auto tensioner, as necessary.
- Disconnect the electrical connectors from the compressor.
- Remove the compressor retaining bolts and nuts.
Remove the compressor from its mounting.
- Installation is the reverse of the removal procedure.
Be sure to use new O-rings coated with clean refrigerant oil.
NOTEOn 1991-1993 vehicles the compressor assembly rear head is redesigned to accommodate new rear seal washers which consist of a special metal washer with a molded rubber seal. When properly installed there is an intentional gap between the facing surfaces of the compressor assembly rear head and the rear head connector block. See illustration.
- Be sure to properly evacuate the air conditioning system.
- Be sure to fill the cooling system with the proper grade and type coolant, as required.
- Using the GM diagnostic scan tool or aftermarket equivalent reprogram the necessary systems and components. Be sure to follow the scan tool manufacturer-s directions.