Grand Marquis V8-281 4.6L SOHC (1992)
Floor Air Distribution Duct
14. Remove one plastic push fastener retaining the floor air distribution duct to the Left Hand end of the plenum. Remove Left Hand screw and loosen
Right Hand screw on the rear face of the plenum, and remove the floor air distribution duct.
15. Remove two nuts from the two studs along the lower flange of the plenum.
16. Carefully move plenum REARWARD to allow heater core tubes and the stud at the top of the plenum to clear holes in the dash panel. Remove
plenum from vehicle by ROTATING the TOP of the plenum FORWARD, DOWN and OUT from UNDER the instrument panel. Carefully PULL
lower edge of 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 evaporator case.
3. Install three nuts on the studs along the lower flange and one on the upper flange of the plenum.
4. Install three nuts below the windshield wiper motor to attach the Left Hand end of the plenum to the dash panel.
5. Install one nut to retain the upper Left Hand corner of the evaporator case to the dash panel.
6. Position floor air distribution duct on plenum. Install two screws and plastic push fastener.
7. If removed, position panel door vacuum motor to the mounting bracket. Install two retaining screws.
8. Connect the white vacuum hose to the outside-recirculating door vacuum motor.
9. Connect the vacuum jumper harness to the plenum harness at the multiple vacuum connector near the floor air distribution duct. Install floor duct.
10. Connect the temperature control cable housing to the bracket on top of the plenum and connect the temperature control cable to the temperature
