Rear

Before testing the rear blower motor switch, verify that the front A/C system is functional by performing the ATC Function Test using the DRBIII(R) scan tool. Use a volt/ohmmeter to test the rear blower motor switch. 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: ON VEHICLES EQUIPPED WITH AIR-BAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Disconnect and isolate the battery negative cable.
2. Unplug the wire harness connector from the rear blower motor switch.
3. Check for continuity between terminal 10 and terminals 1, 7 and 4 of the blower motor switch. In all instances, there should be continuity.

NOTE: To check the switch's internal circuits, connect the negative lead of the ohmmeter to terminal 10 and the positive ohmmeter lead to terminals 1, 7 and 4. To check the switch's integral light emitting diodes, reverse the ohmmeter leads.

4. Check for continuity between the rear blower motor switch terminals 3 and 7 as you move the blower motor switch to each of the two speed positions, and the Off position. There should be continuity in only one blower motor switch speed position.
5. Check for continuity between the rear blower motor switch terminals 4 and 8 as you move the blower motor switch to each of the two speed positions, and the Off position. There should be continuity in only the other blower motor switch speed position.
6. If OK, test and repair the rear blower motor switch wire harness circuits. If not OK, replace the faulty rear blower motor switch.