GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2006 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Mode Door Replacement - Upper

Removal Procedure
  1. Remove the I/P carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages, and Console.
  2. Remove the heater assembly cover screws.
  3. Remove the heater assembly cover.

    4. Object Number: 691864 Size: SH
  4. Disconnect the vacuum hose from the upper mode actuator (1).
  5. Remove the upper mode actuator (1) from the heater assembly (4).
  6. Remove the linkage from the upper mode actuator (1).

    7. Object Number: 691841 Size: SH
  7. Remove the upper mode door (2) from the heater module (1).

Installation Procedure

    Object Number: 691841 Size: SH
  1. Install the upper mode door (2) to the heater module (1).
  2. Install the heater assembly cover.

    3. 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 heater assembly cover screws.

    4. Tighten
    Tighten screws to 1.9 N·m (17 lb in).


    Object Number: 691864 Size: SH
  4. Install the linkage to the upper mode actuator (1).
  5. Install the upper mode actuator (1) to the heater assembly (4).
  6. Connect the vacuum hose to the upper mode actuator (1).
  7. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages, and Console.