I'm currently working on the project(s) in my signature, which are a 72 and 71 Supreme that I'm turning into one drivable car. The 71 that I'm taking parts off has power windows, where all but the driver's side door window works. I knew this for a long time, and decided to test the electrical motors after taking apart the doors for sanding.

With both motor assemblies out of the doors and in hand, I took the driver's side motor and plugged in into the passenger side wire and attempted to make it move. Made sure the battery was connected again, and did my best to make it move - no luck. The rear windows still moved regardless, so it wasn't a problem with the power or the switch, as far as I could tell. For good measure, I took the passenger side motor and hooked it up to the (previously working) passenger side wire, and... nothing. Not the lightest reaction. This has left me utterly perplexed, since that combo of motor and wire worked fine before I took the door off. Have I overlooked something here? I'm at a loss.

Thanks.

 

Start with the obvious and work backwards. Is the fuse good? Did you have a good ground when testing the motor on the passenger side? Get a voltmeter and/or test light (both cheap must-haves) to see if you get 12V at each motor terminal. If not, work your way back towards the harness/fuse block until you find the problem. Switches can sometimes be revived with a good cleaning.

 

I did indeed not have my voltmeter with me, but I'll try that this weekend. Asking for the "obvious hints" is the most effective thing I can do while I'm away from home during the week. Thanks. :P

 

Totally agree. Almost exclusively the grounds were the biggest problems related to power accessories on these cars. If the motor was not properly grounded when you tried it, it won't work. The windows apparently have good grounds.

Switches can be taken apart and cleaned. The pins do get corroded after years of non use or humidity. Good idea to start by spraying them with electrical contact cleaner, then go from there.

 

Wow, hold on, for them to be grounded, I'd have to have part of the window motor "assembly" touching the chassis of the car? That'd explain my problem beautifully, because they we laying on the floor beside the car, not in any contact.

 

On the drivers side, check the wires under the 'flexible' loom from the cowl to the door - I've found many broken wires there!

 

Seff, I probably should have said easiest instead of obvious, hope that did not sound condescending. Just hate to see major work or money thrown at a problem until the simple solutions are checked first. Definitely need some sort of chassis ground to test it and then move on from there.

Wish the easy stuff worked on my interior lights, still tracking that gremlin....

 

Yes and no. If you have it outside the car, just connect the motor to a good ground (like a vice on the workbench?). The car will work fine as long as you aren't trying to ground to metal that's got paint covering it. You can use a wire to act as a ground between the motor and good bare metal. If you are going to ground the motor to the chassis, also make sure the surface on the motor where you're going to touch the chassis is clean metal too. Light sandpaper to clean any grease or rust before you test.

Once you've got the motor working, make sure your ground connection to the chassis is clean. Smear a little dialectric grease on the connection for good measure when you bolt it down.

 

Gotcha, I'll get cracking in the weekend.

Dane: I wasn't offended in the least, so no worries. :P