Control Assembly: Testing and Inspection

Wire Type

Fan switch







1. Remove the heater control unit.
2. Check for continuity between the fan switch terminals by using an ohmmeter.
3. If not as specified, replace the fan switch.

A/C switch







1. Remove the A/C switch.
2. Inspect for continuity between the A/C switch terminals by using an ohmmeter.
3. Turn the A/C switch on.
4. Connect battery positive voltage to terminal F and ground to terminal D.
5. Verify that the LED illuminates.
6. If not as specified, replace the A/C switch.

Logic Type
1. Remove the heater control unit.
2. Reconnect the connector.
3. Measure the voltage at the heater control unit terminals as indicated.
4. To inspect the continuity of terminal J, disconnect the heater control unit connector.
5. If not as specified, inspect the parts listed under "Inspection area" and the related wiring harnesses.
6. If the pans and wiring harnesses are OK but the system still does not work properly, replace the heater control unit.




Terminal voltage list (reference)