Operation CHARM: Car repair manuals for everyone.
Home >> Chevrolet >> 2007 >> TrailBlazer 4WD L6-4.2L >> Repair and Diagnosis >> Heating and Air Conditioning >> Housing Assembly HVAC >> Service and Repair
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Housing Assembly HVAC: Service and Repair



HVAC Module Assembly Replacement

Tools Required

* J43181 Heater Line Quick Connect Release Tool
* J39400-A Halogen Leak Detector

Removal Procedure

1. Drain the engine coolant. Refer to Draining and Filling Cooling System (LL8) Draining and Filling Cooling System (LH6, LS2).
2. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging.
3. Remove the instrument panel (I/P) carrier.
4. Reposition the heater hose clamps using J43181.
5. Disconnect the heater hoses from the heater core.




6. Remove the retaining nut (3) from the accumulator (6) at the evaporator (1).
7. Disconnect the accumulator (6) from the evaporator (1).
8. Disconnect the evaporator tube (4) from the evaporator (1).
9. Disconnect all of the electrical connectors to the HVAC module assembly.
10. Remove the HVAC module assembly.

Installation Procedure




1. If replacing the HVAC module assembly (8), transfer the components from the old HVAC module assembly as necessary.
2. Install the HVAC module assembly (8).
3. Connect all of the electrical connectors to the HVAC module assembly.




4. Connect the heater hoses to the heater core.
5. Connect the evaporator tube (4) to the evaporator (1).
6. Install the accumulator (6) to the evaporator (1).

Notice: Refer to Fastener Notice.

7. Tighten the accumulator retaining nut.

Tighten the nut to 4.5 N.m (40 lb in).

8. Install the I/P carrier.
10. Leak test the fittings of the components using the J39400-A.
11. Refill the engine coolant. Refer to Draining and Filling Cooling System (LL8) Draining and Filling Cooling System (LH6, LS2).
pro multis · About Operation CHARM