In the last couple of weeks I've read and reread bunches of DII window motor/regulator stories but this one is different from the others, I think.

Our older son has had the truck at the beach this summer. A couple of weeks ago he called and told me the passenger-side front window would not go up or down when the switch was pressed. The motor sounded normal but didn't move the window. He was able to push the glass to the fully-up position with no difficulty and it stayed in place so he left it alone until he got back to Charlotte a couple of days ago.

Yesterday we removed the regulator and motor. Everything looked fine except that one of the plastic rollers was broken but that didn't seem to be the problem. What was left of the roller was still held in place in the track.

The gear teeth on the regulator were in great shape and the gear teeth on the motor looked fine too. We bench-tested the motor and regulator using a 12v, 2 amp power supply and it seemed to work fine.

I was going to order the 3D-printed rollers from Shapeways but today we reinstalled the motor and regulator and again everything sounded fine but the window didn't move.

This is where the story is different from the others I've read, I think. What was left of the roller kept it in the track. The motor and regulator played nicely together when out of the truck but not when installed with the glass bolted to it. Could it be that something inside the motor allows it to work fine when under only a light load but not with the "full" load of the glass to move?

We ran out of time to do anything else today, but it seemed odd that everything worked as it should on the bench but not when installed and under load.

We may be able to test the load/no load dilemma further tomorrow in situ by disconnecting the glass and sliding it up with the motor and regulator still installed. If it moves with no load one of us can try to (carefully) hold in place the track to which window attaches while the other activates the switch to see what happens.

I suppose some of you would say to hell with it and just order a new motor/regulator assembly but I have two things working against doing that. I'm the child of Depression-era parents married in 1935 and I grew up in the Great Plains. Both factors built me into a person who tries to figure out how to get things done without just throwing money and parts at the problem.

I'll report back here when I have something to add, but in the meantime if any of you have any info about something inside the motor that would cause its output gear to not turn under load while the motor itself seems to run and sound fine please let me and the rest of us here know. Thanks.

 

Bad ground on the car?

 

This is strange. Could it be the motor shaft slipping in the center of the gear?

 

No, the motor runs and sounds fine installed. It just doesn't move the window. Nor does it prevent the window being moved manually when attached.

 

I think I know your problem because I'm having the same one right now.

Pull your window motor back out and pop off this metal cap:



I'm willing to bet that the rubber cog inside had ripped the middle out. I'm in the process of seeing if I can just remove it and fill in the whole gap with epoxy to make it work. I filled it in last time I was home and I will do it one more time next time I'm home before I reinstall. Fingers crossed that it works. Like yours, motor ran and sounded fine. Unless that's what you already checked, in which case nevermind. ¯\_(ツ)_/¯

 

I've seen this a number of times, for whatever reason the window motor bench tests fine but does not have enough power to push a window up especially against the tension of the window channel felt.

replace the motor and you will be good.

 

Alex's post got me curious about looking at the motor internals. Well not the motor, but its attached "gearbox."

My son is now gone with the truck until late tomorrow at least so I can't look at the problem motor for now, but I happen to have a spare driver's side motor lying around so I looked at removing the metal cap to have a look inside.

I'd always assumed the gearing was somehow sealed tight, but the metal cap popped off as easily as removing the metal cap off a new tube of wheel bearing grease.

What I found is a simple reduction gear setup, with the motor spinning a brass-looking worm gear engaging a white nylon ring gear.

The fact that the motor drives the regulator with no load means that the nylon ring gear isn't completely gone, but perhaps its teeth are just enough damaged that they hold under a light load but fail under a full load.

Perhaps even though the failed roller doesn't appear to be causing a problem now it may have caused the mechanism to bind at one time or another and damage the ring gear.

I'll test and report on the failed setup on the truck once I have it back and have time to get to it.

Stay tuned.

 

The bad roller with weight of window may cause it to stall and not run.
.....

 

Again, it "runs" and sounds normal. It just doesn't move the window, in either direction.

 

I just worked on my friends 03 D2 and when he dropped it off none of the windows worked. LF was completely INOP (found 3 wires broken in the door loom), RF window would go down and sound smooth, however on the way up it would buzz and if you assisted it the buzz would stop and the window would close. LR was the same story as the RF as it would go down smoothly with no noise, on the way up it would go maybe 2-3 inches and buzz, assist it by hand and it would close. RR wasn't moving and it was disconnected electronically due to a completely destroyed window regulator.

On the RF & LR I removed the entire assemblies and bench tested them. Motors ran smooth, and I couldn't stop the gear by hand, regulators did have broken guide wheels, but they were still rolling inside the tracks. Replaced the regulators, installed them into the D2 and instantly got the buzz again. Apparently the internal gears, or something inside is slipping when installed with the weight of the glass and fighting gravity.

I ended up getting two new motors and called it a day. I think when the regulators caused more stress to the motor it internally failed.

If you grab em at a junk yard normally you can get good motors from the rear windows as most people don't ever really open/close those.

You can get new replacements for around 30.00 online.

Kinda reminds me of my daughters F150 Raptor Power Wheels lol. She complained one day that it wouldn't go up a little hill. 99% of the time she never drove it over there and it was fine. Well one day I saw her try the little hill and sure enough her Raptor would just buzz/grind and not climb the little hill. I told her we needed to fix her Ford lol. I removed the wheels to expose the electric motors, and once I took the buzzing unit apart I found it had completely destroyed one of the nylon/plastic gears. I had to order a new unit and her Ford was on the road again and climbs the hill like crazy.

So I'm assuming that somewhere inside of those window motors is a gear that is worn down just enough that under load it skips and the buzzing I heard was the gears binding together vs meshing together properly. 60.00 and good as new was fine with me as the originals lasted a very long time. If you can find em at a junk yard (rear motors) you could probably walk out for 25.00 for both if not less.