How do you replace a heater core on a 1996 crown vic?

Answer 1

1. Disconnect the negative battery cable.

2. Drain the cooling system and disconnect the heater hoses from the heater core tubes. Plug the hoses and the heater core tubes to prevent coolant leakage.
3. Remove the 3 nuts located below the windshield wiper motor attaching the left end of the plenum to the dash panel. Remove the 1 nut retaining the upper left corner of the evaporator case to the dash panel.
4. Disconnect the vacuum supply hose(s) from the vacuum source. Push the grommet and vacuum supply hose(s) into the passenger compartment.
5. Remove the right and left lower instrument panel insulators.
6. Remove all instrument panel mounting screws and pull the instrument panel back as far as it will go without disconnecting any wiring harnesses.
7. Make sure the nuts attaching the instrument panel braces to the dash panel are removed.
8. Loosen the right door sill plate and remove the right side cowl trim panel.
9. If equipped with manual air conditioning, disengage the temperature control cable housing from the bracket on top of the plenum. Disconnect the cable from the temperature blend door crank arm.
10. If equipped with Automatic Temperature Control (ATC), proceed as follows:
    1. On 1989 vehicles, disconnect the temperature control cable from the ATC sensor.
    2. Detach the vacuum harness line connector from the ATC sensor harness and detach the electrical connector from the ATC servo connector.
    3. On 1990-98 vehicles, remove the cross body brace and disconnect the wiring harness from the temperature blend door actuator. Detach the ATC sensor tube from the evaporator case connector.
    
    
    
11. Detach the vacuum jumper harness at the multiple vacuum connector near the floor air distribution duct.
12. Disconnect the white vacuum hose from the outside-recirculating door vacuum motor.
13. Remove the 2 hush panels.
14. Remove 1 plastic push fastener retaining the floor air distribution duct to the left end of the plenum.
15. Remove the left screw and loosen the right screw on the rear face of the plenum and remove the floor air distribution duct.
16. Remove the 2 nuts from the 2 studs along the lower flange of the plenum.
17. 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. 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.
18. On 1989 vehicles with ATC, remove the ATC servo from the plenum.
19. Remove the 4 retaining screws from the heater core cover and remove the cover from the plenum assembly.
20. Pull the heater core and seal assembly from the plenum assembly