Unusual Window Switch Issue
 

So my driver's side passenger window switch stopped working reliably, and got worse over a period of months until most of the time it wouldn't respond. Tried cleaning the contacts and when that didn't work ordered a "Made in Germany" switch from ebay.

The new switch looked pretty good, but when installed it worked normally for only a few seconds and then stopped. When I insisted, it began to spark pretty badly, so I assumed the switch was defective. Reinstalled the old switch; didn't work consistently, but no sparks.

Was sent a replacement switch and same story--works for a little bit and then stops, followed by sparks. Still no visible sparks from the original switch.

The obvious thing to do is to test one of the working switches, but the sparks are worrying. The wiring looks like it's in good condition and the fuse wasn't tripped. So what else could be causing the sparking? It's unlikely both replacement switches are bad, but who knows. I suspect based on the condition of both boxes and some scoring on the connections that they're used, but visually they're very clean. I had assumed they were new when purchased.

Is there some kind of relay that could be failing? It's an 87.

i think you should really look at the window motor ,there could be a short....all this sparking and the fuse did not go bad??

Ivan

What you don't mention is if the passenger door switch on passenger door works, ie if the window can be lifted and lowered normally with pass switch.

If so, that would rule out the window motor.
Unless I missed the info.

Also, does your driver side window still work? If so, that would rule out the relay, since it controls power to both sides.

Check the wiring at the door hinge area, where it goes into the car body.

Thanks, The passenger side switch works fine. I checked the connection at the door hinge and it's dusty, but fully seated. Haven't removed it.

The driver's side also works fine, thanks for helping me rule out the relay, Gilles.

I guess I'll have to try one of the other switches. Any ideas what could be causing the switches to spark? Could it be caused by frayed wiring somewhere out of sight? The weird thing is immediately after I install the switches the window operates fine for a bit before it randomly stops.

just a idea, are your wires connected correctly? if i remember... right bottom brown ,left bottom red together connected with right top, middle blue with black on left, blue right....

Passenger side switch works fine and consistently, so that rules out the motor too.
The driver side switch for passenger side is the one that receives power from the relay and then distributes it to other switches. Don't know if that is of interest in your case.
Anyway here is the schematic for this model year. Hope that helps.
http://forums.pelicanparts.com/uploa...1697141190.png

Some good info here:
https://blog.*******.com/how-to-replace-power-window-switches-on-an-air-cooled-porsche-911

it's blog.*******.

https://blog.*******.com/how-to-replace-power-window-switches-on-an-air-cooled-porsche-911

eff see pee dot com.............censor nannies here.

https://forums.pelicanparts.com/porsche-911-technical-forum/184531-power-window-switch-wiring.html

Also here.

http://forums.pelicanparts.com/porsche-911-technical-forum/682755-odd-power-window-issue.html

Are you sure that 2 of the contacts are not touching each other or maybe one of the wires is touching the metal brace that holds the switch in place? Is the rubber boot present behind the switch?

Thanks, guys. It's wired how it's always been wired, and it worked for years, so I assume it's right. The wires are colored differently. I have red blue on the top and lower left, brown(?) with white stripe on middle left, red on middle right. and ground on lower right.

Now that you mention it, the rubber boots weren't perfect. I wrapped a couple in electrical tape, but the ground wire boot is bit torn. It's possible two of the contacts were touching. But it still doesn't tell us why the switches don't seem to work.

Appreciate the helpful schematic and links. I'll take a look and try again tonight. Maybe I'll remove the driver's side switch and test that. But after my fire episode last month, the sparks really freak me out. I replaced that same switch a couple years ago and it wasn't a problem. It's a bit frustrating.

For wiring, refer to pin numbers stamped on switch and follow with numbers shown on schematic. Referring to position up down, center, etc. is prone to error.

Also, if you have an ohmmeter, check switch continuity and isolation between pins on the various positions: rest, up and down. Again by referring to the schematic that shows the internals of the switch.

^

I went through the same song and dance with my 88. Your dealing with a motor issue. You would be surprised how hard the grease in the motor case can get over time.

Sure, but he said window motor works fine when operated from the passenger side switch. So that should rule out motor and mechanical issues in general.

^
Nice....thank's I skimmed the thread.

Again, check the wiring in the drivers door hinge. Chances are that one (or more) of the wires has frayed or broken in the hinge area (underneath the plastic sheathing) and is making an intermittent contact. Ohm check the wires while moving the wiring harness and opening and closing the door.

Also remember that on model years 86-89, windows can be operated while the ignition key is off or even removed to the condition that one of the doors or both are open. Not when all doors are closed.

yup did not read it correctly-not the motor ...as said above must be the wires pinched somewhere

Ivan

I had frayed wires in the door, just behind the grommet where they pass through.

I'll have a careful look at the wires in the door later tonight. It would explain why the switch would suddenly start/stop working for periods of time. Appreciate all the support.

So it's definitely not the switch. Tested against the working driver's side switch, same result. The switches all behave the same way--they'll work for about 20 seconds and then stop. I verified that all the connections were solid and the position of the door makes no difference. The sparking was an unrelated issue that must have been caused by wires touching; wrapped any exposed metal in electrical tape and no more sparks from any of the stitches.

The wiring in the door looks fine and the passenger side switch works reliably. If the two passenger window switches are associated, is it possible the problem is a loose connection on the passenger side?

Make sure all you connections are 100% accurate wire to switch ...

Check if the window lower support-rail is attached to the window.. if the motor is working and the window is not moving up.

Let us know what you find.

Thanks Kraftwerk. I'll double check, but I'm pretty sure they're accurate. The support rail seems to be ok, since the window operates normally with the passenger side switch. the only time the passenger side switch didn't work was when the driver's side passenger switch was completely detached, so I assume power runs through the driver's passenger window switch.

There have been times when the switch would die for a little while, but it would always come back and work for extended periods. This time the working time is down to almost zero. Every time I connect a new switch, it will operate for a few second and then stop as if the motor isn't getting enough power from the driver's side. The passenger side switch does the job with no problem. Maybe it is in fact a weakening motor, as a couple people have suggested.

Weakening motor combined with the spring not resting on its rivet ( "rivet fell-off" is super common! )
Awhile back, I got a new switch which looked really cheaply made, it had defects... not all switches are equal ~ !

I thought that too, but a known working switch does the same thing. I really hope I'm missing a simple fix. Replacing the motor would be a drag.

In case anyone is interested, the problem in fact turned out to be a defect in the passenger side window switch causing it to stick and eventually fail.

Replaced; all three switches working better than ever since.