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How To Diagnose Power Window Problem - Is the Switch or Motor bad?

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  1. step : Diagnosing the Window Motor (0:16)
    • Ground the test light to the vehicle body
    • Turn the vehicle on
    • Test that the switch is receiving power with the test light
    • Test the two wires from the switch to the window motor, while pressing the switch
    • Test that power is being received at the window motor connector, while pressing the switch
    • If the switch and motor are receiving power, but the motor doesn't work, the motor is the problem
    • Connect the window motor connector to a new window motor
    • Try to run the new window motor with the switch to confirm that the old motor is the problem

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Hi, I'm Mike from 1A Auto. I hope this how-to video helps you out, and next time you need parts for your vehicle, think of Thanks.

Turn the key on. You can see my driver side power window motor is not working. So I'm going to diagnose what's not working here. I've got a test light, make a good ground with the vehicle. Here's my switch, I put this- I just took the switch off the door panel and put it on here. First you want to find the power wire, so I've got the key on in the vehicle, so the power is on in the vehicle. You can see that there's power there. I'm just probing that. I hit the metal and that light comes on, I have power there. Okay, at this first step I've confirmed that I have power to the switch.

If you were not able to find that you have power to the switch, then you would need to look for either a break in the wire between the body and the door. Usually if you pull the little boot back that protects the wires that run from between the body and the door you'll find a break in the wire. The other thing is you could have a blown fuse. You've kind of ruled out step one, you've got power to the switch so power is getting to the door.

There's power going into the switch but nothing's happening. All right, so if I look here at my power window motor I've got an orange with a white stripe and I have an orange with a green stripe. Coming out of the switch, there's orange white stripe and orange green stripe. I can probe the orange with white stripe. Let's see here. See I'm holding the switch. I let the switch out, so power is going to the orange with white stripe. Power is going to the orange with green stripe. Now at this point we've ruled out the second thing which is the switch. We know the switch is good. Power is coming into the switch. You activate the switch one way, one of the wires lights up, you activate the switch the other way, the other wire lights up so the switch is doing its job. It's directing the power from the main power supply to whichever wire to run the motor that you want.

Come down here. Probe the back of the orange with white stripe. You see power's going to the motor. Power's going to the motor, so there's nothing wrong with the switch it's got to be the motor. So I was able to deduce that it was the motor because I know there's power going into the switch, I know there's power coming out of the switch, and I know there's no breaks in the wires between the switch and the motor, because when I flip the switch I'm able to light up the light at the connector at the motor, so it has to be the motor that's bad.

We can confirm that pretty easily. We've got our new regulator with motor here from 1A Auto. We're going to press down on the tab here. Disconnect and then connect that right here, and you can hear very easily, as soon as we hit the switch, this motor is working.

Thanks for tuning in. We hope this video helped you out. Next time you need parts for your car, please visit Also, check out our other helpful how-to, as well as, diagnosis videos.

Tools needed for replacement:

    Diagnostic Tools

  • Test Light

Voltage Circuit Test Light

Test Light Performance Tool Performance Tool

This part replaces:

  • Performance Tool W2975C

Part Details

  • Lead Length: 42 in. Lead Wire
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