A/C-HEATER CONTROL ASSEMBLY
- Disconnect negative battery cable and wait at least 90 seconds. Remove instrument cluster finish center panel with A/C-heater control assembly attached. Remove A/C-heater control assembly.
- Check continuity or resistance between specified terminals. See «A/C-HEATER CONTROL ASSEMBLY TESTING»(ref-125179-S31198809302001100400000) table. (Scheme 8) Because A/C-heater control assembly switches may have one-way diodes, check continuity in both directions before replacing switch.
| Switch Position | Between Terminals | Result | |
|---|---|---|---|
| Air Inlet Control Switch | |||
| Fresh | A20 & A9 | Continuity | |
| Recirculate | A16 & A9 | Continuity | |
| Mode Control Switch | |||
| Face | A14 & B16 | Continuity | |
| Bi-Level | A12 & B16 | Continuity | |
| Foot | A17 & B16 | Continuity | |
| Foot/Defrost | B11 & B16 | Continuity | |
| Defrost | B4 & B16 | Continuity | |
| Blower Switch | |||
| Off | A10 & B16 | Continuity | |
| Low | A2, A1 & B16 | Continuity | |
| Medium-Low | B15, A1 & B16 | Continuity | |
| Medium-High | B14, A1 & B16 | Continuity | |
| High | B13, A1 & B16 | Continuity | |
| A/C Switch | |||
| Off | B6, B16 & B17 | No Continuity | |
| Off | B8 & B18 | No Continuity | |
| On | B6, B16 & B17 | Continuity | |
| On | B8 & B18 | Continuity | |
| Temp. Control Switch | |||
| Always | B1 & B2 | About 3000 Ohms | |
| Cool | B1 & B3 | Zero Ohms | |
| Hot | B1 & B3 | (1) About 3000 Ohms | |
| (1) Resistance should increase from zero ohms to about 3000 ohms as temperature control lever is moved from cool position to hot position. | |||
| (1) | Resistance should increase from zero ohms to about 3000 ohms as temperature control lever is moved from cool position to hot position. |
A/C-HEATER CONTROL ASSEMBLY TESTING
Scheme 8
Disassembly
Release spring clips holding covers together. Remove any screws at case joints. Separate upper and lower cases from evaporator core. see scheme 16 Remove Allen bolt from expansion valve, and remove expansion valve.
Remove 4 screws and air vent duct. see scheme 17 Remove engine coolant temperature sensor harness. Disconnect air mix servomotor control link, and remove air mix servomotor. Remove heater core pipe clamps and heater core. Remove air outlet servomotor, aspirator, foot air duct, and engine coolant temperature sensor.