Window Motor Keeps Dying

[stoopalini]

When I got this car (1990 GT Convert), the driver's side window motor was non-functional. I assume this was due to the top having a tear over the driver's door and water getting in, as the armrest was completely shot as well.

I bought a new Dorman motor from RockAuto and replaced it in Feb 2012. I also installed new bushings in the window track and re-greased everything. The window worked great after this.

In June of 2014, the window stopped working again. Pressing the button would produce a click from the motor, but no movement. I order another replacement motor, this time from LateModelRestoration, and by the time I went to replace it, it had started working again; but I decided to replace it anyway.

It's been working great since, until yesterday when it stopped again. Same symptoms, with the motor making a click when I press the window button, but no movement.

I removed the switch unit and OHM'ed out the switches, and they appear to be fine.

Any idea what I'm dealing with here?

 

[stoopalini]

Well, I opened up the door and applied 12v directly to the motor and it works. I then metered out the connector and pushed the window switch, and I got 12v out of it. So I reconnected the motor and it's working now?

The connectors are pretty clean, but I scratched them up anyway, applied some dialectic grease, reconnected it, and it's working fine now. Hopefully it was just a bad connection.

 

[doobismaximus]

Sounds like you got it knocked out. My rear motors work, but i have to help them up, which is hard to hit the button and pull up passenger side one. Friend says i need new regulators for both. Being you have a vert, have you any insight?

 

[stoopalini]

I had similar issues with my quarter windows when I bought the car.

I bought the quarter window guide resto kit from LMR and cleaned/greased everything up when I installed the pieces. They work like new now.

 

[stoopalini]

Well, this problem re-appeared yesterday. I haven't taken the door panel back off yet, but I'm assuming I'll have the same findings as last time.

Any ideas what could be causing this?

 

[91TwighlightGT]

If your switch is good (they can be intermittent and are less than $10 as I recall so if you are in doubt just replace it) and the motor works with 12V applied, then it is going to be either corroded/worn connectors or a broken/corroded wire between the switch and the motor.

If it were mine, I would replace the switch and see how it goes. If it still gives trouble, then have a helper hold the switch down while you move the wires around and see if you can pinpoint a bad connection. Or try to replace the harness if you can find a known good one.

 

[stoopalini]

Thanks for the info. Any idea where I can find a wiring diagram of the window switches and motors? I noticed the wire boot between the door and the body is torn, so it's probable I'm dealing with a bad connection somewhere in the harness.