Blower Motor: Testing and Inspection

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. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY OR DEATH.

Possible causes of an inoperative front or rear blower motor include:
- Faulty fuse (the rear blower motor fuse is located in the relay and fuse block located on the back of the junction block)
- Faulty blower motor circuit wiring or wire harness connectors
- Faulty blower motor resistor block
- Faulty blower motor relay (Voltage Reduction Relay or VRR) (front only)
- Faulty blower motor switch
- Faulty heater-A/C mode control switch (front only)
- Faulty blower motor.

Possible causes of the front or rear blower motor not operating in all speeds include:
- Faulty fuse (the rear blower motor fuse is located in the relay and fuse block located on the back of the junction block)
- Faulty blower motor switch
- Faulty blower motor resistor block
- Faulty blower motor relay (front only)
- Faulty blower motor circuit wiring or wire harness connectors

VIBRATION
Possible causes of front or rear blower motor vibration include:
- Improper blower motor mounting
- Improper blower wheel mounting
- Blower wheel out of balance or deformed
- Foreign material in blower wheel causing out of balance condition
- Blower motor faulty.

NOISE
To determine if the front or rear blower motor is the source of the noise, simply switch the front or rear blower motor from Off to On. To verify that the blower motor is the source of the noise, unplug the blower motor wire harness connector and operate the heater-A/C system. If the noise goes away, possible causes include:
- Foreign material in the HVAC housing
- Improper blower motor mounting
- Improper blower wheel mounting
- Blower motor faulty.