GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2002 🢒 Century 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Defroster Door Replacement

Removal Procedure
  1. Remove the instrument panel trim pad. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gages and Console.
  2. Remove the passenger side SIR inflator module. Refer to Inflatable Restraint Instrument Panel Module Replacement in SIR.
  3. Remove the brake pedal. Refer to Brake Pedal Replacement in Hydraulic Brakes.
  4. Remove the bolts from the steering column support bracket and remove the bracket.

    5. Object Number: 283722 Size: SH
  5. Remove the screws from the right and left side air distribution ducts.
  6. Remove the air distribution ducts.

    7. Object Number: 486677 Size: SH
  7. Remove the bolts from the relay bracket and position the relay bracket aside.

    8. Object Number: 486680 Size: SH
  8. Remove the bolts from the BCM bracket and position the BCM bracket aside.
  9. Release the wiring harness retaining clips from the cross vehicle beam and position the wiring harness aside.
  10. Remove the two screws below the fuse block that hold the main harness connector to the cross vehicle beam.

    11. Object Number: 282301 Size: SH
  11. Remove the bolts from the center support bracket of the HVAC module.
  12. Remove the center support bracket of the HVAC module.

    13. Object Number: 482597 Size: SH
  13. Remove the bolts from the upper support brackets of the HVAC module.

    14. Object Number: 482587 Size: SH
  14. Remove the bolts which secure the left cross vehicle beam to the hinge pillar.

    15. Object Number: 482588 Size: SH
  15. Remove the bolts which secure the right cross vehicle beam to the hinge pillar.

    16. Object Number: 811571 Size: SH
  16. Remove the bolt (1) from the cross vehicle beam.
  17. Remove the cross vehicle beam from the vehicle.

    18. Object Number: 708587 Size: SH
  18. Disconnect the 2 vacuum lines from the defroster actuator (3).
  19. Disconnect the orange vacuum line from the recirculation actuator and install a hand vacuum pump (2).
  20. Remove the defroster actuator from its attachment to the HVAC module case.
  21. Using the hand vacuum pump (2) open the recirculation actuator door.
  22. Rotate the defroster actuator to the right and up into the opening between the back of the dash and the opening into the HVAC module. The opening which results when the recirculation actuator door is in the full open position.
  23. Disconnect the defroster actuator from the defroster door arm.

    24. Object Number: 295281 Size: SH
  24. Disconnect the vacuum lines from the mode actuator.
  25. Lift the lock tab up (1) to remove the actuator.
  26. Remove the mode actuator off the slides of the HVAC module assembly.
  27. Disconnect the actuator pushrod from the mode door lever and remove the actuator.

    28. Object Number: 607130 Size: SH
  28. Remove the retaining screws (1) from the air distribution case cover.
  29. Remove the air distribution case cover (2).
  30. Remove and discard the air distribution case seal.
  31. Remove the linkage between the defroster door and the heater door on the left side of the HVAC module assembly.

    32. Object Number: 607136 Size: SH
  32. Remove the defroster door (1).

Installation Procedure

    Object Number: 607136 Size: SH

    Important: Align the defroster door assist spring to the HVAC module assembly case.

  1. Install the defroster door (1).
  2. Connect the linkage between the defroster door and the heater door.
  3. Install a new air distribution case seal.

    4. Object Number: 607130 Size: SH
  4. Install the air distribution case cover (2).

    5. 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.

  5. Install the air distributor cover retaining screws (1).

    6. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).


    Object Number: 708587 Size: SH
  6. Connect the orange vacuum line to a hand vacuum pump (2).
  7. Using the hand vacuum pump (2) open the recirculation actuator door.
  8. Rotate the defroster actuator to the right and up into the opening between the back of the dash and the opening into the HVAC module. The opening which results when the recirculation actuator door is in the full open position.
  9. Connect the defroster actuator to the defroster door arm.
  10. Position the defroster actuator on to the mounting slides of the HVAC module assembly.
  11. Ensure that the lock tab locks the defroster actuator in place.
  12. Connect the vacuum lines to the defroster actuator.
  13. Connect the vacuum line to the recirculation actuator.

    14. Object Number: 295292 Size: SH
  14. Connect the mode actuator pushrod to the mode door lever.
  15. Position the mode actuator on to the mounting slides of the HVAC module assembly.
  16. Ensure that the lock tab locks the defroster actuator in place.
  17. Connect the vacuum lines to the mode actuator.

    18. Object Number: 482600 Size: SH
  18. Install the cross vehicle beam to the vehicle.

    19. Object Number: 482588 Size: SH
  19. Install the bolts which secure the right cross vehicle beam to the hinge pillar. Tighten the bolts finger tight.

    20. Object Number: 482587 Size: SH
  20. Install the bolts which secure the left cross vehicle beam to the hinge pillar. Tighten the bolts finger tight.

    21. Tighten
    Tighten all the bolts to 20 N·m (15 lb ft).


    Object Number: 811571 Size: SH
  21. Install the bolt (1) to the cross vehicle beam.

    22. Tighten
    Tighten the bolt to 20 N·m (15 lb ft).


    Object Number: 482597 Size: SH
  22. Install the bolts to the upper support brackets of the HVAC module.

    23. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 282301 Size: SH
  23. Install the center support bracket to the HVAC module.
  24. Install the bolts to the center support bracket of the HVAC module.

    25. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  25. Install the instrument panel wiring harness on to the cross vehicle beam and secure the retaining clips.
  26. Install the two screws below the fuse block that hold the main wire harness connector to the cross vehicle beam.

    27. Object Number: 486680 Size: SH
  27. Install the BCM bracket and the bolts.

    28. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 486677 Size: SH
  28. Install the relay bracket and the bolts.

    29. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 283722 Size: SH
  29. Install the right and left side air distribution duct bolts.

    30. Tighten
    Tighten the bolts to 1.5 N·m (13 lb in).


    Object Number: 637312 Size: SH
  30. Install the support bracket for the steering column.

    31. Tighten
    Tighten the bolts to 50 N·m (37 lb ft).

  31. Install the brake pedal. Refer to Brake Pedal Replacement in Hydraulic Brakes.
  32. Install the passenger side SIR inflator module. Refer to Inflatable Restraint Instrument Panel Module Replacement in SIR.
  33. Install the instrument panel trim pad. Refer to Instrument Panel Trim Pad Replacement in Instrument Panel, Gages and Console.