How to Test a Car's Blower Motor

Your blowers are responsible for circulating warm or cold air into the passenger cabin. When there's a problem, it can make for uncomfortable rides, especially in extreme temperatures. Avoid problems by putting the motor through a diagnostic test.

Instructions

1

Listen for the sound of the motor. If you don't hear sound, it could be a bad resistor, a blown fuse or a loose wire.

2

Replace any blown fuses. Turn on the motor and watch the new fuse. If it immediately blows, you have an electrical short. If it lasts a while but then blows, you probably should replace the brushes on the motor.

3

Pull out the motor if the fuses are functioning. Check for loose wires. If these aren't loose, hook jumper wires to the motor. Attach one wire to a ground and another to a power source. Replace the motor if it doesn't start.

4

Turn on your heat if the motor and fuses work. Listen and feel at the vents for air. Switch on your air conditioning. If you don't get air, your motor might have clogged or the air controls may be defective. Use a scan tool to check the air controls. If you don't have a scan tool, bring the car to a mechanic.