Blower Motor Switch: Testing and Inspection

BLOWER MOTOR SWITCH - REAR

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 AIRBAGS, 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 AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Remove the accessory switch plate from the instrument panel.Check for continuity between the ground circuit cavity of the rear blower motor switch wire harness connector and a good ground. There should be continuity. If OK, go to Step 2. If not OK, repair the open circuit to ground as required.
2. With the rear blower motor switch wire harness connector unplugged, place the rear blower motor switch knob in any position except the OFF position. Check for continuity between the ground circuit terminal and each of the blower motor driver circuit terminals of the rear blower motor switch as you move the blower motor switch knob to each of the three speed positions. There should be continuity at each driver circuit terminal in only one blower motor switch speed position. If OK, test and repair the rear blower driver circuits between the rear blower motor switch wire harness connector and the rear blower motor resistor or the rear high speed blower motor relay as required. If not OK, replace the faulty rear blower motor switch.