GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Chevy C Cab/Chassis HD (GMT 400) 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Heater/Vent Module Replacement

Removal Procedure
  1. Remove the center floor air distribution duct.

    2. Object Number: 276537 Size: SH
  2. Remove the retainer screw.
  3. Remove the trim panel from the retainers.
  4. Roll back the instrument panel. Refer to Instrument Panel Assembly Replacement in Instrument Panel, Gages and Console.
  5. Remove the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement in Engine Cooling.
  6. Remove the inlet heater hose clamp from the heater core.
  7. Remove the inlet heater hose from the heater core.
  8. Remove the outlet heater hose clamp from the heater core.
  9. Remove the outlet heater hose from the heater core.

    10. Object Number: 257083 Size: SH
  10. While holding the HVAC module to the cowl, remove the screw on the interior side of the cowl, near the evaporator pipe.

    11. Object Number: 257087 Size: SH
  11. On the engine side of the cowl, remove the 4 screws that hold the HVAC module to the cowl.
  12. On the engine side of the cowl, remove the 2 nuts that hold the HVAC module to the cowl.
  13. Remove the HVAC module.

Installation Procedure
  1. Install the HVAC module.

    2. Object Number: 257087 Size: SH
  2. On the engine side of the cowl, install the nuts that hold the HVAC module to the cowl.
  3. On the engine side of the cowl, install the 4 screws that hold the HVAC module to the cowl.

    4. Object Number: 257083 Size: SH
  4. On the interior side of the cowl, install the bolt.

    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. Tighten the following fasteners:

    6. Tighten

        • Tighten the screws on the engine side of the cowl to 1.9 N·m (17 lb in).
        • Tighten the 2 nuts to 2.8 N·m (25 lb in).
        • Tighten the bolt on the interior side of the cowl to 11 N·m (97 lb in).
  6. Install the outlet heater hose to the heater core.
  7. Install the outlet heater hose to the heater core.
  8. Install the inlet heater hose to the heater core.
  9. Install the inlet heater hose to the heater core.
  10. Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement in Engine Cooling.
  11. Roll forward the instrument panel. Refer to Instrument Panel Assembly Replacement in Instrument Panel, Gages and Console.

    12. Object Number: 276537 Size: SH
  12. Install the trim panel to the retainers.
  13. Install the retainer screw.

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

  14. Install the center floor air distribution duct.