GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 HVAC 🢒 Heating, Ventilation, and Air Conditioning 🢒 Heater Assembly Replacement

Removal Procedure
  1. Remove the evaporator and blower module assembly. Refer to Air Conditioning (A/C) Evaporator and Blower Module Assembly Replacement .

    2. Object Number: 815372 Size: SH
  2. Remove the heater assembly retaining nuts (1) from the engine compartment.
  3. Remove the I/P carrier. Refer to Instrument Panel Carrier Replacement.
  4. Disconnect the temperature actuator electrical connector.
  5. Disconnect the vacuum lines from the actuators.
  6. Remove the heater assembly.

Installation Procedure

    Object Number: 815372 Size: SH
  1. Install the heater assembly.
  2. Connect the vacuum lines to the actuators.
  3. Connect the temperature actuator electrical connector.
  4. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement .

    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 heater assembly retaining nuts (2) to the engine compartment.

    6. Tighten
    Tighten the nuts to 6 N·m (53 lb in).

  6. Install the evaporator and blower module assembly. Refer to Air Conditioning (A/C) Evaporator and Blower Module Assembly Replacement .