John Markowitz

Hi All-

I have a 1991 928-S4.

My driver's side window suddenly got stuck all the way down-no slowing beforehand, no nothing. You can here the switch clicking clearly. Switch itself however is just fine-tried on other door-no problem.

The only thing less than my mechanical ability is my patience! I'll go for minor stuff but that's about it.

Anyway, any suggestions on what it may be beyond a bad window motor? I just want to be prepared for the shop next week and at least act like I know what the hell I'm talking about!! And if anybodyhas a thought on how to get this window up an shut......

Thanks in advance-

John
Charleston, SC

worf928

If you know that the switch is good, barring electrical connector corrosion, the only two possibilities are the window controller under the seat or the window motor. If the harness to the motor (behind the door panel) is getting 12v switched with the window switch - then its the motor. If not, then its the controller. Note that 928s older than MY 90 do not have a window controller (and thus your mechanic may be unaware of its existence.)

I just replaced the window motor on my '91. It's not a tough job. If you've never taken the door panel off yourself, figure a day. If you have taken the panel off then its an hour to get the motor out and back in once the panel and vapor barrier is off.

worf928

There is a good write up on removing the door panel on the Nichols site. It is not a tough job with the write-up. Doing the job yourself will give you the opportunity to replace the felt on the window guides and the nylon bushings and rubber stop on the window guide tube (no more window rattles.)

Ketchmi

A quick test on the motor is to bang on the bottom of the door just below and behind the light. (where it's flat against the door, not the raised area above it) I have had several limit switches fail and giving them a thump while holding the switch in the up position usually get's them working again. If you don't put it all the way down afterwards you will not have the same problem until you can get in there and do a proper fix.

Brett Matthews

I had the same problem, but reversed, stuck in the up position. Ended up that a piece of rust? grit? junk anyways, got stuck in the window motor. Took me a few hours to remove the door panel and remove the motor. It came out easier than I was told! Disassembled the motor just to see what was in there, and this large piece of junk was in there! Removed it, cleaned all the old grease out, relubed with some waterproof grease, reassembled, and the motor works better than it ever did before. I'm mechanically inclined, not electrically inclined, so I was surprised at how easy it really was.

And the window is still working fine.

worf928

Dave, I'm always interested in learning something new. But, I cannot find anything limit-switch-like shown on the wiring diagrams wired into the window motor?

Alan

John,
Before heroics - hold the button down for 6 seconds in close-mode...

The later '89+ window controller has a closed /crush detector (detects the current spike when the motor stalls) and cuts out - this is how it knows to stop when the window gets to the top and in sequence it moves to the next window as needed... If the mechanism/guides/rollers etc get too stiff it may think it's hit the top...(or found an arm!) There is a 5 second override expecially for cases like this....

Try - it may just work...

Alan

John Markowitz

Well, I tried the ketchmi suggestion last evening (i.e. banging on the door panel) without any joy-although it was nice to hit something after screwing around with this problem half the day. Then early this morning, I was going to try Alan's suggestion of simply holding down the switch in the "up" position for 6 seconds. Well this morning the window immediately just came right on up-smoothly as ever-didn't have to wait at all.

But now its stuck all the way UP !

I prefer this to stuck down for sure, but before I take it in to the shop (and I have no choice but the Porsche dealer here), any further suggestions/thoughts on what the likely culprit is, cures, etc???

Its obviously not the switch (as I changed it out yesterday which didn't help then) and it is an intermittent problem. Sound like motor issue or....other possibilities?

Thanks in advance-

John Markowitz
Charleston, SC

1991 928 S4
Amazon Green Metallic

Alan

Try the 6 second thing for down too (the window motor load sensing works the same either way).

If that works - I'd say you have some stiffness/binding - worth door panel removal - motor removal lube motor (inside can), lube mechanism/gears. With the window down clean out the window channels.

Really it sounds like cooling off may have just freed it up a bit....

Other possibility is a motor connecton issue (outside or inside) - clean internal contacts with switch cleaner/contact cleaner once you have it open to lube.

Alan

John Markowitz

Thanks Alan-

Yeah, In tried that one no luck. I think if I do have to do surgery on the door-and its looking that way, I may as well replace the motor I suppose. I have a parking garage card, and that think goes all the way up and down twice every single day and I'm guessing its the original at 15 years old.......

Thoughts on the window controller "under the seat" a few folks mentioned? What's its purpose and chances of being the culprit if you know?

Thanks-

John

Randy V

I knew I shouldn't have read this thread yesterday.

Got in the car today and the driver's side window is stuck in the closed position!

I can hear the controller clicking. The 6-second push and the 'door bang' technique didn't fix it.

worf928

John, like Randy said - if you can hear the controller clicking then it is probably the motor.

Once the door panel is off, before you peal back the vapor barrier you can check for 12v at the harness going to the motor. If you get 12v - and check to make sure that the polarity swaps with the switch - then its the motor. Green and Green/Red (on the body harness side) are the wire colors (for both the '91 and '94)

The wiring diagram shows a single unbroken harness from the controller to the harness connector behind the door panel - so there's no other easy place to test. You might also be able to check for 12v at the controller connector. The seat might have to come out - I've never looked at it.

Randy - if you decide to take out your seat beware of over-torqued seat bolts. EVERY seat bolt on my '94 is over-torqued and seized and there's no indication that the seats have ever been out or needed to come out. In contrast the bolts on my '89 and '91 came out fine.

worf928

John, the window controller that appeared under the seat as of MY '90 is what gives you the one-touch down feature along with being able to close the windows and sunroof with the key (and probably some other features I don't recall right now.)

Alan

BTW this happened to me about 4 years ago. Motor totally dead - controller seemed OK and I took the door apart. Power to the motor was OK... I took the motor out and apart - I could see no issues - cleaned & lubed it - put it back in and its worked perfectly for the last 4 years... Try cleaning it first - it may not need replacement. In the end I have no idea what my problem was...

Alan

Ron_H

Been down this road before. Alan, you were lucky that cleaning the motor solved the problem. I wasn't so lucky, and finally simply changed it with a spare motor I had laying around. No problems for about two years, and I use the passenger window alot. Easy to replace.