With Automatic Temperature Control (ATC)
REMOVAL1. Disconnect the battery ground cable.
2. Disconnect the heater hoses from the heater core tubes and position them for minimum coolant loss.
3. Plug the heater core tubes securely to prevent coolant leakage from the heater core during the plenum removal.
Plenum And Air Inlet Duct:
4. Remove the three nuts located below the windshield wiper motor attaching the LH end of the plenum to the dash panel.
5. Remove one nut retaining the upper LH corner of the evaporator case to the dash panel.
6. Disconnect the control system vacuum supply hose from the vacuum source. Push the grommet and the vacuum supply hose into the passenger compartment.
7. Remove the RH and the LH lower instrument panel insulators.
8. Remove the three glove compartment hinge screws, disconnect the check strap, and remove the glove compartment.
9. Loosen the RH doorsill plate and remove the RH side cowl trim panel.
10. Remove the bolt attaching the lower RH end of the instrument panel to the side cowl.
11. Remove the instrument panel pad.
12. Disconnect the temperature control cable from the Automatic Temperature Control (ATC) sensor.
13. Disconnect the vacuum harness line connector from the ATC sensor harness and disconnect the electrical plug from the ATC servo plug.
14. Disconnect the ATC sensor tube from the temperature sensor and the evaporator case connector.
15. Disconnect the vacuum jumper harness at the multiple vacuum connector near the floor air distribution duct.
16. Disconnect the white vacuum hose from the outside-recirculate door vacuum motor.
17. Remove the two screws attaching the passenger (rear) side of the floor air distribution duct to the plenum. It may be necessary to remove the two screws attaching the partial (lower) panel door vacuum motor to the mounting bracket to gain access to the RH screw.
18. Remove one plastic push fastener retaining the floor air distribution duct to the LH end of the plenum and two screws on the rear face of the plenum (Fig. 24), and remove the floor air distribution duct.
19. Remove the two nuts from the two studs along the lower flange of the plenum.
20. Carefully move the plenum rearward to allow the heater core tubes and the stud at the top of the plenum to clear the holes in the dash panel.
NOTE: Remove the plenum from the vehicle by rotating the top of the plenum forward, down and out from under the instrument panel. Carefully pull the lower edge of the instrument panel rearward as necessary while rolling the plenum from behind the instrument panel.
INSTALLATION
1. Route the vacuum supply hose through the dash panel and seat the grommet in the opening.
2. Position the plenum under the instrument panel with the register duct opening up and the heater core tubes down. Rotate the plenum up behind the instrument panel and position the plenum to the dash panel. Insert the heater core tubes and mounting studs through their respective holes in the dash panel and the plenum.
3. Install three nuts on the studs along the lower flange and one nut on the upper flange of the plenum.
4. Install the three nuts below the windshield wiper motor to attach the LH end of the plenum to the dash panel.
5. Install the one nut to retain the upper LH corner of the evaporator case to the dash panel.
6. Position the floor air distribution duct to the plenum. Install the two screws and the plastic push fastener.
7. Position the partial (lower) panel door vacuum motor to the mounting bracket. Install the two attaching screws.
8. Connect the white vacuum hose to the outside recirculate door vacuum motor.
9. Connect the vacuum jumper harness at the multiple vacuum connector near the floor air distribution duct.
10. Connect the temperature control cable to the ATC sensor and adjust the cable.
11. Route and connect the vacuum harness connector to the ATC temperature sensor and connect the electrical plug to the ATC servo plug. Do not block the temperature sensor aspirator exhaust port with the excess vacuum harness.
12. Install the ATC sensor tube between the sensor and the evaporator connector.
13. Install the bolt to attach the lower RH end of the instrument panel to the side cowl.
14. Install the RH side cowl trim panel. Tighten the RH doorsill plate attaching screws.
15. Install the instrument panel pad.
16. Install the glove compartment door.
17. Connect the vacuum supply hose to the vacuum supply fitting.
18. Install the RH and the LH lower instrument panel insulators.
20. Unplug the heater core tubes and connect the heater hoses to the heater core tubes.
20. Fill the cooling system with coolant to replace the coolant lost during removal of the plenum.
21. Connect the battery ground cable.
NOTE: On vehicles equipped with Electronic Engine Control (EEC), when the battery has been disconnected and reconnected, some abnormal drive symptoms may occur while the EEC processor relearns its adaptive strategy. The vehicle may need to be driven 10 miles or more to relearn the strategy.
22. Check the ATC system for proper operation.