GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Discharge and recover the Refrigerant. Refer to Refrigerant Recovery and Recharging.
  3. Drain the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

  4. Object Number: 244231  Size: SH
  5. Remove the heater hoses (2,3) at the heater core.

  6. Object Number: 833674  Size: SH

    Important: Cap the open fittings in order to prevent dirt and moisture from entering the refrigeration system.

  7. Remove the evaporator inlet (4) and outlet (3) tubes from the evaporator.
  8. Remove the instrument panel assembly. Refer to Instrument Panel Upper Trim Pad Replacement and Instrument Panel Lower Trim Panel Replacement in Instrument Panel, Gages, and Console.
  9. Remove the instrument panel reinforcement. Refer to Instrument Panel Carrier Support Replacement in Instrument Panel, Gages, and Console.
  10. Disconnect the blower motor electrical connector.

  11. Object Number: 834531  Size: SH
  12. Separate the rear heater ducts (3) from the HVAC module assembly (1).
  13. Remove the four nuts (2).
  14. Pull the HVAC module assembly forward and remove from the vehicle.

Installation Procedure


    Object Number: 834531  Size: SH
  1. Install the HVAC module assembly (1) to the vehicle.
  2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the four nuts (2).
  4. Tighten
    Tighten the nuts (2) to 10 N·m (89 lb in).

  5. Connect the rear heater ducts (3) to the HVAC module assembly (1).
  6. Connect the blower motor electrical connector.
  7. Install the instrument panel reinforcement. Refer to Instrument Panel Carrier Support Replacement in Instrument Panel, Gages, and Console.
  8. Install the instrument panel assembly. Refer to Instrument Panel Lower Trim Panel Replacement and Instrument Panel Upper Trim Pad Replacement in Instrument Panel, Gages, and Console.
  9. Install new O-rings lubricated with mineral base 525 viscosity refrigerant oil.

  10. Object Number: 833674  Size: SH
  11. Install the evaporator inlet (4) and outlet (3) tubes to the evaporator.

  12. Object Number: 244231  Size: SH
  13. Install the heater hoses  (2,3) to the heater core.
  14. Fill the cooling system. Refer to Cooling System Draining and Filling .
  15. Evacuate and Recharge the A/C system. Refer to Refrigerant Recovery and Recharging.
  16. Connect the negative battery cable.
  17. Tighten
    Tighten the negative battery cable to 15 N·m (11 lb ft).

  18. Operate the A/C system and test for refrigerant leaks. Refer to Leak Testing .