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Here is the procedure to get the housing out of the truck, then you open the case and remove the core.

INSTRUMENT PANEL ASSEMBLY

Removal

NOTE: Before starting this procedure, be certain to turn the steering wheel until the front wheels are in the straight-ahead position.

1. Disconnect and isolate the battery negative cable.

2. Remove the Airbag Control Module (ACM) and bracket from the floor panel transmission tunnel.

3. Remove the trim from the left and right cowl side inner panels.

4. Remove the steering column opening cover from the instrument panel.

5. Remove the two screws that secure the inside hood latch release handle to the instrument panel lower reinforcement and lower the release handle to the floor.

6. Disconnect the clockspring pigtail wire connector from the instrument panel wire harness connector located on the instrument panel lower reinforcement.

7. If the vehicle is so equipped, disconnect the overdrive lockout switch pigtail wire connector from the instrument panel wire harness connector near the instrument panel lower reinforcement.

8. Remove the steering column from the vehicle, but do not remove the driver airbag, the steering wheel, or the switches from the column. Be certain that the steering wheel is locked and secured from rotation to prevent the loss of clockspring centering.

9. From under the driver side of the instrument panel, perform following:

a. Disengage the park brake release handle linkage rod from the park brake mechanism on the left cowl side inner panel.

b. Disconnect the instrument panel wire harness connector from the park brake switch on the park brake mechanism.
c. Disconnect the three connectors (one from the body wire harness, and two from the headlamp and dash wire harness) from the three connector receptacles located closest to the dash panel on the back of the Junction Block (JB).
d. Remove the screw from the center of the headlamp and dash wire harness to instrument panel wire harness bulkhead connector and disconnect the connector.
e. Disconnect the instrument panel wire harness to door wire harness connector located directly below the instrument panel wire harness to headlamp and dash wire harness bulkhead connector.
f. If the vehicle is equipped with the Infinity sound system option, disconnect the infinity wire harness connector from the instrument panel wire harness connector that is secured to the outboard side of the instrument panel wire harness to headlamp and dash wire harness bulkhead connector.
g. Disconnect the instrument panel wire harness connector from the stop lamp switch.
h. Disconnect the heater-A/C housing vacuum harness connector from the heater-A/C control vacuum harness connector located near the left end of the heater-A/C housing.

10. From under the passenger side of the instrument panel, disconnect the two halves of the radio antenna coaxial cable connector.





11. Loosen the right and left instrument panel cowl side roll-down bracket screws about 13 mm (0.50 inch).

12. Remove the five screws that secure the top of the instrument panel to the top of the dash panel, removing the center screw last.

13. Roll down the instrument panel and install a temporary hook in the center hole on top of the instrument panel. Secure the other end of the hook to the center hole in the top of the dash panel. The hook should support the instrument panel in its rolled down position about 46 cm (18 inches) from the dash panel.

14. With the instrument panel supported in the roll-down position, disconnect the instrument panel wire harness connectors from the heater-A/C housing wire harness connectors.

15. With the aid of an assistant, remove the temporary hook and life the instrument panel assembly off of the roll-down bracket screws and remove it from the vehicle.

REMOVAL


The HVAC housing assembly must be removed from the vehicle and disassembled for service access of the heater core, a/c evaporator, and each of the various mode control doors.

1. Disconnect and isolate the battery negative cable.
2. Remove the dash board from the vehicle.

3. If the vehicle is not equipped with air conditioning, go to Step 6. If the vehicle is equipped with air conditioning, recover the refrigerant from the system,

4. Disconnect the liquid line refrigerant line fitting from the evaporator inlet tube. Install plugs in, or tape over all of the opened refrigerant line fittings.
5. Remove the accumulator. Install plugs in, or tape over all of the opened refrigerant line fittings.
6. Drain the engine cooling system.
7. Disconnect the heater hoses from the heater core tubes. Install plugs in, or tape over the opened heater core tubes.
8. Remove the Powertrain Control Module (PCM) from the dash panel and set it aside, but do not unplug the PCM wire harness connectors,

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

10. Remove the nuts that secure the HVAC housing to the mounting studs on the passenger compartment side of the dash panel.
11. Pull the HVAC housing rearward far enough for the mounting studs and the evaporator condensate drain tube to clear the dash panel holes.
12. Remove the HVAC housing from the vehicle.

HVAC Housing Inlet Baffle
1. Remove the HVAC housing from the vehicle.

2. Slide the HVAC housing inlet baffle all the way to one side of the cowl plenum opening.
3. Pull downwards sharply and firmly on the opposite side of the HVAC housing inlet baffle to disengage the snap features from the cowl plenum opening.
4. Remove the HVAC housing inlet baffle from the cowl plenum panel.

INSTALLATION
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 nuts that secure the HVAC housing to the mounting studs on the passenger compartment side of the dash panel. Tighten the nuts to 4.5 Nm (40 in. lbs.).
3. 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.).
4. Unplug or remove the tape from the heater core tubes. Connect the heater hoses to the heater core tubes and fill the engine cooling system. Refer Cooling for the procedures.
5. If the vehicle is not equipped with air conditioning, go to Step 10. If the vehicle is equipped with air conditioning, install the accumulator. Connect the accumulator inlet tube coupler to the evaporator outlet tube.
6. Unplug or remove the tape from the liquid line and the evaporator inlet tube fittings. Connect the liquid line coupler to the evaporator inlet tube.
7. Evacuate the refrigerant system.
8. Charge the refrigerant system,

9. Reinstall the PCM to the dash panel,

10. Reinstall the dash board in the vehicle.

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

HVAC Housing Inlet Baffle
1. Install the HVAC housing inlet baffle in the cowl plenum panel.
2. Slide the HVAC housing inlet baffle to engage the snap features.
3. Make certain that the snap features on each side of the adapter are fully engaged with the sides of the plenum panel opening. This must be a water tight connection to prevent leaks.
4. Install the HVAC housing in the vehicle.