GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure


    Object Number: 588295  Size: SH
  1. Recover the A/C system. Refer to Refrigerant Recovery and Recharging .
  2. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  4. Remove the evaporator hose assembly from the evaporator. Refer to Air Conditioning Evaporator Hose Assembly Replacement .
  5. Remove the heater hoses from the heater core. Refer to Heater Hoses Replacement .
  6. Remove the drain tube elbow from the evaporator block heater case plate.

  7. Object Number: 588299  Size: SH
  8. Remove the nuts holding the heater case plate for the heater pipes.
  9. Remove the heater case plate and the seals for the heater pipes.
  10. Remove the nuts holding the heater case plate for the evaporator block.
  11. Remove the heater case plate and seal for the evaporator block.
  12. Remove the nut for the HVAC module assembly bracket.
  13. Lower the vehicle.
  14. Remove the instrument panel (IP) carrier. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gauges, and Console.
  15. Remove the air distribution duct. Refer to Air Distributor Duct Replacement .
  16. Remove the floor air duct from the HVAC module assembly. Refer to Floor Air Outlet Replacement .
  17. Remove the cross vehicle beam (tie bar). Refer to Instrument Panel Tie Bar Replacement in Instrument Panel, Gauges, and Console.

  18. Object Number: 590288  Size: SH
  19. Remove the daytime running lights (DRL) sensor wiring harness clip (1) from the HVAC module assembly.
  20. Disconnect the IP lamp dimmer switch electrical connector (2).
  21. Remove the wiring harness clips (3) from the HVAC module assembly bracket.
  22. Disconnect the vacuum hose (4) from the vacuum tank.

  23. Object Number: 588308  Size: SH
  24. Disconnect the blower motor resistor electrical connector.
  25. Disconnect the blower motor electrical connector.

  26. Object Number: 590302  Size: SH
  27. Disconnect the temperature actuator electrical connector.

  28. Object Number: 592637  Size: SH
  29. Remove the HVAC module assembly.

Installation Procedure


    Object Number: 592637  Size: SH
  1. Position the HVAC module assembly to the vehicle.

  2. Object Number: 590302  Size: SH
  3. Connect the temperature actuator electrical connector.

  4. Object Number: 588308  Size: SH
  5. Connect the blower motor resistor electrical connector.
  6. Connect the blower motor electrical connector.

  7. Object Number: 590288  Size: SH
  8. Install the wiring harness clips (3) to the HVAC module assembly bracket.
  9. Install the daytime running lights (DRL) sensor wiring harness clip (1) from the HVAC module assembly.
  10. Connect the IP lamp dimmer switch electrical connector (2).
  11. Install the vacuum hose (4) to the vacuum tank.

  12. Object Number: 588299  Size: SH
  13. Install the cross vehicle beam (tie bar). Refer to Instrument Panel Tie Bar Replacement in Instrument Panel, Gauges, and Console.
  14. Install the floor air duct to the HVAC module assembly. Refer to Floor Air Outlet Replacement .
  15. Install the air distribution duct. Refer to Air Distributor Duct Replacement .
  16. Install the instrument panel (IP) carrier. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gauges, and Console.
  17. Raise the vehicle.
  18. Notice: Refer to Fastener Notice in the Preface section.

  19. Install the nut for the HVAC module assembly bracket.
  20. Tighten
    Tighten the bracket nut to 10 N·m (88 lb in).

  21. Install the heater case plate and the seals for the heater pipes.
  22. Install the nuts holding the heater case plate for the heater pipes.
  23. Install the heater case plate and seal for the evaporator block.
  24. Install the nuts holding the heater case plate for the evaporator block.
  25. Tighten
    Tighten the heater case plates nuts to 10 N·m (88 lb in).


    Object Number: 588295  Size: SH
  26. Install the drain tube elbow to the evaporator block heater case plate.
  27. Install the evaporator hose to the evaporator. Refer to Air Conditioning Evaporator Hose Assembly Replacement .
  28. Install the heater hoses to the heater core. Refer to Heater Hoses Replacement .
  29. Lower the vehicle.
  30. Fill the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  31. Evacuate and recharge the refrigerant system. Refer to Refrigerant Recovery and Recharging .
  32. Leak test the fittings of the component using the J 39400-A .