Section 12-02: Heating and Defrosting
1996 F-150, F-250, F-350, F-Super Duty and Bronco, F-Super Duty Motorhome Chassis Workshop Manual
REMOVAL AND INSTALLATION

Air Plenum Chamber and Duct

Removal

  1. NOTE: On some vehicles it may be necessary to remove the lower right attaching screw and the screws attaching the two braces to the lower center area of the instrument panel (04320).

    Loosen all of the retaining screws. Refer to Section 01-12. Move the instrument panel rearward to gain access to the heater air plenum chamber (18471). Remove the glove compartment.

  1. Remove the heater outlet floor duct (18C433) from the heater air plenum chamber. Refer to Outlet Floor Duct in the Removal and Installation portion of this section.

  1. Remove the four fasteners that retain the left end of the heater air plenum chamber to the dash panel.

  1. Disconnect the A/C temperature cable (19988) and vacuum connector at the heater control (18549).



    Temperature Cable Removal — Heater Control




  1. Disconnect the source vacuum block that is secured to the right side of the heater core cover (18B300).

  1. Pull the heater plenum chamber case (18A484) forward to disengage three studs from the dash panel.

  1. NOTE: Care must be taken to avoid spilling any coolant from the heater core (18476).

    Lower the heater air plenum chamber from its location under the instrument panel.

Installation

  1. Position the heater air plenum chamber against the dash panel. Install one screw to attach the left end of heater air plenum chamber to dash panel.

  1. Position the heater plenum chamber case against the dash panel, making sure that the studs are inserted through holes in the dash panel and flange.

  1. Position the instrument panel and tighten its retaining screws.

  1. Snap the A/C temperature cable into the cable mounting bracket on the heater air plenum chamber, making sure temperature blend door actuator post is aligned within the A/C temperature cable head cam.

  1. Connect the control vacuum and source vacuum.

  1. Position the heater outlet floor duct and install its pushpin.

  1. Install the glove compartment.

  1. Check the system for proper operation.



    Heater Blower Motor and Heater Plenum Chamber, Installation





    ItemPart NumberDescription
    118471Heater Air Plenum Chamber
    218C433Heater Outlet Floor Duct
    301610Dash Panel
    418A484Heater Plenum Chamber Case
    5N612906-S2Nut (4 Req'd)
    6N803912-S2Stud (2 Req'd)