Blower Motor Switch: Testing and Inspection

For circuit descriptions and diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out 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 ON position and check for battery voltage at the fuse in the fuse block module. If OK, go to Step 2. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
2. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Remove the heater-A/C control from the instrument panel, but do not unplug the wire harness connectors. Connect the battery negative cable. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run) circuit cavity of the heater-A/C mode control switch wire harness connector. If OK, go to Step 3. If not OK, repair the open circuit to the fuse block module as required.
3. Select any one of the heater-A/C mode control positions except OFF to turn the system ON. Check for battery voltage at the low blower motor driver circuit cavity of the heater-A/C mode control switch wire harness connector. If OK, go to Step 4. If not OK, replace the faulty heater-A/C mode control switch.
4. Check for battery voltage at the low blower motor driver circuit cavity of the blower motor switch wire harness connector. If OK, go to Step 5. If not OK, repair the open circuit to the heater-A/C mode control switch wire harness connector as required.
5. Check for battery voltage at each of the remaining blower motor switch wire harness connector cavities as you move the switch to each blower motor speed position. Voltage should be present in each cavity at only one switch position. If OK, see the diagnosis for the blower motor resistor and/or the blower motor relay in this group. If not OK, replace the faulty blower motor switch.