Automatic Temperature Control (ATC)

Fig. 15 Removing center distribution duct & cover assembly. Horizon & Omni:

1. Drain coolant and discharge A/C system. Disconnect battery ground cable.
2. Disconnect blend air door cable and unfasten from clip on heated air duct.
3. Remove glove box, then the center bezel assembly.
4. Remove center distribution duct then the defroster duct adapter.

Fig. 16 Evaporator-heater retaining nuts. Horizon & Omni:

5. Disconnect refrigerant lines and heater hoses from dash panel. Plug heater hoses to prevent leakage.
6. Disconnect vacuum lines from engine and water valve.
7. Remove four evaporator heater assembly-to-dash retaining nuts.

Fig. 17 Evaporator-heater assembly. Horizon & Omni:

8. Remove right side cowl trim panel, then the right instrument panel pivot bracket screw.
9. Remove two steering column-to-lower instrument panel attaching screws, then the upper panel cover.
10. Remove all except left panel-to-fenceline attaching screws, then pull back carpet as far as possible from under evaporator heater assembly.
11. Support evaporator heater assembly, then remove support strap nut, blower motor ground cable and strap.









12. Lift assembly and pull rearward as far as possible to clear dash panel and liner. Have an assistant pull panel rearward to provide sufficient clearance for removal of the unit.
13. Carefully lower assembly, taking care to prevent studs from catching in dash liner.
14. With assembly on floor, slide rearward until instrument panel is cleared.
15. Place evaporator heater unit on bench, then remove blend air door pivot shaft retaining nut.
16. Unfasten crank from pivot shaft using suitable pliers.
17. Disconnect vacuum lines from defrost and panel mode vacuum actuators and position lines aside.
18. Remove 16 evaporator heater assembly cover attaching screws and the cover.
19. Remove nut from bottom of blend air door pivot shaft, then remove blend air door from assembly.
20. Remove heater core seal and the heater core.
21. Remove expansion valve seal and retaining screw from under sealing plate, then lift evaporator core out of assembly.
22. Reverse procedure to install.