Removal and Replacement

REMOVAL
The HVAC housing assembly must be removed from the vehicle and the two halves of the housing separated for service access of the heater core, evaporator coil, blend door(s), and each of the various mode doors.

WARNING:
- ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
- REVIEW THE WARNINGS AND CAUTIONS IN PLUMBING BEFORE PERFORMING THE FOLLOWING OPERATION. Service Precautions

1. Disconnect and isolate the battery negative cable.
2. Remove the instrument panel from the vehicle. Refer to: Body and Frame, Interior Trim, Dashboard/Instrument Panel, Service and Repair, Instrument Panel Service Procedures, Instrument Panel Assembly Replacement, Instrument Panel Assembly

3. Recover the refrigerant from the refrigerant system. Service and Repair
4. Disconnect the liquid line refrigerant line from the evaporator inlet tube. Install plugs in, or tape over all of the opened refrigerant line fittings. Service and Repair
5. Disconnect the suction line refrigerant line from the evaporator outlet tube. Install plugs in, or tape over all of the opened refrigerant line fittings. Service and Repair
6. Disconnect the heater hoses from the heater core tubes. Clamp off the heater hoses to prevent loss of coolant. Install plugs in, or tape over the opened heater core tubes.
7. If the vehicle is equipped with the manual temperature control system, unplug the HVAC system vacuum supply line connector from the tee fitting near the heater core tubes.
8. Remove the coolant reserve/overflow bottle from the passenger side inner fender shield. Coolant Reservoir
9. Remove the Powertrain Control Module (PCM) from the passenger side dash panel in the engine compartment and set it aside. Do not unplug the PCM wire harness connectors. Service and Repair

Fig.9 HVAC Housing - (rear view):

10. Remove the nuts from the HVAC housing mounting studs on the engine compartment side of the dash panel.

Fig.10 Rear Floor Ducts:

11. Remove the rear floor heat ducts from the floor heat duct outlets.
12. Unplug the HVAC housing wire harness connectors.

Fig.11 Passenger Side Instrument Panel To Heater - A/C Housing Mounting:

13. Remove the HVAC housing mounting nuts from the studs on the passenger compartment side of the dash panel.
14. Remove the HVAC housing from the vehicle, ensuring that the interior is covered in case of loss of fluids.

INSTALLATION

WARNING: REVIEW THE WARNINGS AND CAUTIONS IN PLUMBING BEFORE PERFORMING THE FOLLOWING OPERATION. Service Precautions

Any kinks or sharp bends in the refrigerant plumbing will reduce the capacity of the entire air conditioning system. Kinks and sharp bends reduce the flow of refrigerant in the system. A good rule for the flexible hose refrigerant lines is to keep the radius of all bends at least ten times the diameter of the hose. In addition, the flexible hose refrigerant lines should be routed so they are at least 80 millimeters (3 inches) from the exhaust manifold.

High pressures are produced in the refrigerant system when the air conditioning compressor is operating. Extreme care must be exercised to make sure that each of the refrigerant system connections is pressure-tight and leak free. It is a good practice to inspect all flexible hose refrigerant lines at least once a year to make sure they are in good condition and properly routed.

1. Position the HVAC housing to the dash panel. Be certain that the evaporator condensate drain tube and the housing mounting studs are inserted into their correct mounting holes.
2. Install the HVAC housing mounting nuts to the studs on the passenger compartment side of the dash panel. Tighten the nuts to 4.5 Nm (40 in. lbs.).
3. Connect the HVAC housing wire harness connectors.
4. Reinstall the rear floor heat ducts to the center floor heat duct outlets.
5. Install and tighten the nuts onto the HVAC housing mounting studs on the engine compartment side of the dash panel. Tighten the nuts to 7 Nm (60 in. lbs.).
6. Reinstall the PCM to the passenger side dash panel in the engine compartment. Service and Repair
7. Reinstall the coolant reserve/overflow bottle to the passenger side inner fender shield. Coolant Reservoir
8. If the vehicle is equipped with the manual temperature control system, connect the HVAC system vacuum supply line connector to the tee fitting near the heater core tubes.
9. Unclamp/unplug the heater core hoses and tubes. Connect the heater hoses to the heater core tubes and fill the engine cooling system. Service and Repair
10. Unplug or remove the tape from the suction line and the evaporator outlet tube fittings. Connect the suction line to the evaporator outlet tube. Tighten retaining nut to 28 Nm (250 in. lbs.).
11. Unplug or remove the tape from the liquid line and the evaporator inlet tube fittings. Connect the liquid line to the evaporator inlet tube. Tighten retaining nut to 28 Nm (250 in. lbs.).
12. Evacuate the refrigerant system. Service and Repair
13. Charge the refrigerant system. Service and Repair
14. Install the instrument panel in the vehicle. Refer to: Body and Frame, Interior Trim, Dashboard/Instrument Panel, Service and Repair, Instrument Panel Service Procedures, Instrument Panel Assembly Replacement, Instrument Panel Assembly

15. Connect the battery negative cable.
16. Start the engine and check for proper operation of the heating and air conditioning systems.