Troubleshooting

• Make sure the voltage is reaching the window motor. Remove the inner door trim to gain access to the motor and expose the wiring harness between the window switch and the motor. If necessary, consult the service manual for your particular vehicle. While you can remove some door panels by prying the trim off the clips, other models require special tools.
  
  Test for voltage at the motor wiring connections using a test light. Keep in mind that some vehicles activate the circuit only with the ignition key in the "On" position. Check for voltage as you press the window switch. If current is reaching the motor, check for a good ground at the motor.
  
  

No Voltage at the Motor

• If your tests show no voltage, check the wiring between the motor and the switch. Look for a possible open or short as well as any corrosion at the wire connections that might be preventing proper current flow.
  
  Again, consult your vehicle's service manual, as some models provide a circuit breaker for each motor in addition to the main circuit breaker or fuse. Make sure the circuit breaker or fuse is still in operating condition by checking for continuity with an ohmmeter.
  
  

Tracing Current Flow

• Check for continuity at the window switch with your ohmmeter; and determine if there's a short or opening in the wiring between the switch and the fuse box, using the test light. Some power window circuits have relays to control current flow. If necessary, use your test light to check for incoming and outgoing voltage at the relay.
  
  

Voltage at the Motor

• If power is reaching the motor, closely inspect the window regulator for binding or damage that might prevent the window from moving up and down. You may need to disconnect the window from the regulator. If the regulator mechanism is working properly and the electrical connections at the motor are clean and tight, you must replace the motor.