Temperature Control

Before testing the rear A/C temperature control, verify that the front A/C system is operating correctly by performing the ATC Function Test using the DRBIII(R) scan tool. Use a volt/ohmmeter to test the control. For circuit descriptions and diagrams, refer

to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

WARNING: TO AVOID PERSONAL INJURY OR DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT TENSIONER, IMPACT SENSOR, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT.

1. Disconnect and isolate the battery negative cable.
2. Unplug the wire harness connector from the rear A/C temperature control.
3. Check for continuity between terminal 9 and terminals 3 and 5 of the A/C temperature control. In all instances, there should be continuity.

NOTE: To check the switch's internal circuits, connect the positive lead of the ohmmeter to terminal 9 and the negative lead to terminals 3 and 5. To check the switches integral light emitting diode, reverse the ohmmeter leads.

4. Check for resistance between terminal 3 and 5 of the A/C temperature control as you move the control to each temperature position. Resistance should be present and should change for each position.
5. If OK, test and repair the rear A/C temperature control wire harness circuits. If not OK, replace the faulty rear A/C temperature control.