GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 605190  Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
  2. Remove the defroster actuator. Refer to Defroster Valve Actuator Replacement .
  3. Remove the defroster valve spring.
  4. Remove the heater/defroster slave valve linkage.

  5. Object Number: 605186  Size: SH
  6. Remove the screw for the mode/defroster valve case cover retainer.
  7. Remove the retainer.

  8. Object Number: 605189  Size: SH
  9. Remove the mode/defroster valve case cover screws.
  10. Remove the mode/defroster valve case cover.

  11. Object Number: 604826  Size: SH
  12. Remove the defroster valve (1) from the module case.
  13. Inspect the defroster valve for damage.

Installation Procedure


    Object Number: 604826  Size: SH
  1. Install the defroster valve (1) to the module case.

  2. Object Number: 605189  Size: SH
  3. Install the mode/defroster valve case cover.
  4. 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 mode/defroster valve case cover screws.
  6. Tighten
    Tighten the cover screws to 1 N·m (9 lb in).


    Object Number: 605186  Size: SH
  7. Install the mode/defroster valve case cover retainer.
  8. Install the screw for the retainer.
  9. Tighten
    Tighten the retainer screws to 1 N·m (9 lb in).


    Object Number: 605190  Size: SH
  10. Install the defroster valve spring.
  11. Install the heater/defroster slave valve linkage.
  12. Install the defroster actuator. Refer to Defroster Valve Actuator Replacement .
  13. Install the HVAC module. Refer to HVAC Module Assembly Replacement .