dan heap

I have a 1988 928S4 auto and the passenger window (its LHD) will not go up or donw when I press the switch. Its obviously stuck down! I've taken the door panel off to reveal motor and tested current to motor when switch is pressed, current in shows in both directions of pressing switch, ie; motor seems to be getting power. What should I do next?
Can the motor be overhauled? Any tips gratefully recieved.

Dan

rixter

pull off the side panels on the center console, disconnect the pass switch at the connector and swap it with the driver side, if the window works it's the switch... order new one

jim morehouse

I've had to replace the window motor on my '88 twice because the switch tends to 'stick'. When it failed on a road trip, I found that if I held the switch down while slamming the door closed, the vibration was enough to have the motor operate. I've seen a thread here in the past that mentioned re-conditioning the motor but don't remember the contents. I just got a used one from 929International.

Jim

Alan

Remove the motor - dissassemble, clean, lube and reassemble - apply power - see if it seems OK... If yes reinstall.

I did this with my drivers side about 3 years ago - same symptoms as yours - it has worked fine - no more issues - I don't know what it was @ fault but its worth a shot...

Alan

svp928

I had that problem with the sticky switch- it actually fried the motor on mine- I ended up getting a replacement also. I never took my motor apart to see what was wrong, so you might try that first.

dan heap

Thanks for the input guys, I'll try the motor strip down. I figured if it's getting power the problem must be at the motor itself. Thanks again dan

John Struthers

Was it the motor?

dan heap

Took out the window motor, applied 12v power from a battery and nothing happened, stripped down the window motor and re-assembled it, tested with the battery again now turns in both directions. Installed it in the door, pressed switch still doesnt work. Connected battery to the motor again and window goes up and down, faulty switch? Before motor strip down motor recieved power when switch was pushed but did not turn, is it not getting enough current via the switch to run? Any thoughts most welcome.

thanks

dan

SteveG

Don't know if your mechanism is the same as a '93. Had mine open for same problem. I had power to the motor for up and down, but no movement. The allenhead nearest the toothed arm is some kind of adjustment. It goes thru the toothed arm/bracket and holds a rubberized flat thingy about 1"X5/8"x1/4" against the toothed arm. As assembled, it is on the outside of the arm and not visible so I'm not sure its function, but I think it is a limit or bumper for same. I loosened it a bit (the allen head now sits 1/8" to the right of where it was. The elec connector to the motor wiggled but fooling with it had no effect, so I'm taking credit for the "adjustment" and it worked throughout the test drive. Mostly I was testing the RMB. I have to test that every chance I get. It always passes the test.

Alan

No an '88 is not like an '89-'95 in the window control department. '88's drive the motor direct from the switch (no relays) and are more prone to contact wearout.

If you are sure you are getting no juice at the motor it is probably the switch (check the fuse though...). Pull the switch from the console and test for juice there as you switch it...

Alan

dan heap

getting power at the motor from the switch, ie connecting a voltmeter across motor terminals shows power in both directions, but when you press the swicth the motor doesn't move. Made 2 leads with spade connectors direct from a battery and the motor turns in both directions. Is this a dodgy switch? I think the switch is letting some power to the motor but not enough to move the window? Any thoughts would be great. I might try the switch overhaul detailed in the tech forum and see what happens. Any way of testing knowing the power needed at the motor to move it?

Thanks

dan

Alan

Dan,
The motor should have 12v on one side and 0V on the other when you operate the switch, operatingit in the opposite direction the 0v/12V should reverse. If the 12v droops much or if it does not get to 0V on the other side either the wiring or the switch is at fault..

Alan

dan heap

Thanks for the mail alan, been away in UK, will do the test you suggest over the weekend and let you know what I find.

thanks again
dan