Blower Motor Test

Blower Motor Test


Disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative 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 may result in accidental airbag deployment and possible serious or fatal injury.

Possible causes of an inoperative front or rear blower motor include:

• Open fuse.

• Inoperative blower motor resistor block or power module (depending on application).

• Inoperative blower motor.

• Inoperative blower motor switch.

• Inoperative heater-A/C mode control switch.

• Blower motor circuit wiring or wire harness connectors.

Possible causes of the front or rear blower motor not operating in all speeds include:

• Inoperative blower motor resistor block or power module (depending on application).

• Inoperative blower motor switch.

• Inoperative blower motor circuit wiring or wire harness connectors.

Vibration

Possible causes of front or rear blower motor vibration include:

• Improper blower motor mounting.

• Blower wheel out of balance or deformed.

• Foreign material in blower wheel causing out of balance condition.

• Worn blower motor.

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:

• Improper blower motor mounting.

• Foreign material in blower wheel.

• Foreign material in housing.

• Worn blower motor.