Rebuilding window motor...help?
 

Hi All,

I'm trying to rebuild my original front-pass-side window motor; I'm just about to give up and buy a new one, but I'm trying to make sure that the one I've got is actually kaput.

When I removed it, it was totally non-functioning. Wouldn't budge. Took it apart, cleaned it, greased it, worked the shaft -- it seemed awful stiff -- and finally got it going, though weakly. As the bearing still seemed stiff, I drilled a small hole in the bottom of the case and put some grease in; this seemed to help quite a bit, and the motor ran stronger, though the shaft was still a bit gritty.

I re-installed it, and tried it out. Lowering the window: successful. Raising it: nothing. After a few more tries I tried pulling up on the window while pressing the switch; now it rose, though anemically. Motor is still weak. I then tried lifting the window myself, but it proved very difficult. Removed the motor, tried moving the window by hand again. Easy. Seems like the motor is the hold up...but the shaft wasn't that hard to turn by hand, so why so much resistance?

Took motor back apart. Shaft was about the same: a little stiff, but smoother than before, not that hard to turn. put motor back together, and gears back in, then tried to turn the small gear that protrudes on the motor. Wouldn't barely budge, even with a big pair of pliers. I'd already removed the nylon bits from the gear housing and put in eight 1/4 nuts, so why is it so hard to turn? Do the bolt cause more resistance than the nylon originals? Is it supposed to be this way?

With the case together, but the gears out -- as close to 'unloaded' as I could get it -- I ran the motor for 25.51 seconds -- yes, I used a stopwatch -- before it stopped. During the last five or six seconds it slowed down progressively, then stopped suddenly: surely the motor's internal thermal relay. Is this suspicious or not? Should these motors run indefinitely, or does the thermal protection normally kick in around thirty seconds?

Argh.

Cheers,
Tim

What did your brushes look like? When the brushes get real short, they will work a bit and then quit because the brush doesn't stay in it's slot properly.