power window electrical questions

[clevy70911T]

I had intermittent driver side PW problems. A few days ago, the driver side stops working altogether. When investigating the switches, the pass side stops working too.

I have power to pin 30 and 87 with the relay out. 87 shouldnt have. 86 gets power with ign on. My fuse 21 doesnt have any wires coming from either post. My windows worked before with the key out, ign off also.

When I run 12V directly to the switches or motor, I still get nothing from the window motor, other than the 12V. I assume it grounds out to the door frame? Pass side, same thing but I havent taken that door panel off yet to get directly to the motor.

The switches seem ok and all grounds are good. One would think that this is a bad motor, but why would the pass side stop working too? 2 failed motors at the same time? I doubt it. I dont get 12v at the switches which would lead me to believe that the is a wire break from the fuse to switch. But when applying 12v directly to switch, I still get nothing other than 12 volts.

Before I take out the driver motor, I need some suggestions from somebody that knows what they're doing.

So somebody tell me what I'm missing here. I have my other car apart changing the timing belt and need to get these windows up at least.

Should I be able to move the window up manually in any way. It wont budge right now. HELP!!!!

Thanks, SCott

1981 911SC

[Mysterytrain]

Scott,
The main power feed for both doors comes into the drivers side on a red wire that goes to terminal 5 on driver's side, passenger door switch. It then daisy chains to terminal 3 and then to terminals 5 & 3 on the drivers door switch. The ground connection for all the switches is from terminal 4. Terminal 2 [red/blk wire] and terminal 1 [red/wht wire] on the drivers side passenger door switch go back out of the the drivers door and travel to the passenger door switch where they are attached to terminals 5 and 3 respectively.
Terminal 1 [black wire] and 2 [green wire] on the drivers side switch and the passenger side switch go to the motors.
If I were you I would pull the door panels and apply 12 volts to each of the motors. If they both work that eliminates the motors. I would then apply power first to terminal 1 and then 2 of the drivers door switch and see if the motor operates. Repeat for the passenger side. This tests the motor harness. If everything is good then apply power to terminal 5 of each switch and attempt to operate the switches. Anyway, you get the idea of working back thru the circuit on section at a time.
There is one additional circuit that might be adding to your problem. I was looking at the PET drawings for SC with power windows and oddly another 'relay harness' [part #4] is shown. I was under the assumption that this 'relay harness' appeared on later cars. The additional relay provided convenience power when the car was turned off and the door opened. This allowed you to power the windows up without using the key...which you said your car did.
I would guess this additional circuit would appear in the carrera bentley because it is not in my factory SC manual nor the SC Bentley.
Your car might have had wiring problems on the main power circuit and was made operational by some crafty rewiring on the convenience relay or the relay itself might have its contacts fused together allowing constant power. The location of the relay is behind the instruments.

http://www.pelicanparts.com/911/911_Parts/Electrical/911_electrical_82SC_Part4-2.jpg

[kepperly]

Very Very seldom do the mtrs go out, the problem is 90% the switch's, and also its the cheap fix that you don't have to take the door panels off to repair. Buy two new switch's from our host and I would bet it fixes it.

Keith Epperly
87 slant nose turbo look Carrera cabriolet

[rusnak]

hope this goes through

[rusnak]

I wonder if it's a bad ignition switch, since you said the power worked with the key out?

Also, you might try eliminating the relay as a problem by jumpering the pins with a piece if wire and plug connectors.

If it's the ignition switch, I just changed mine and have some pointers for you.

[Robby Robinson]

Scott, My owner's manual suggests you can crank up the window manually by removing the small speaker in the door, then pierce the plastic membrane. Take crank and hexagon reducing socket from toolkit and push hex socket into crank, turn crank to raise window.

That's from an 88 Carrera manual. Robby

[clevy70911T]

Thanks everyone very much. I don't have to jumper the relay as it has power on both sides already. That could be a fused terminal in the relay socket. Jumpered it anyway and went back to switch, nothing. Directly wired from fuse box power source and then from the battery and still nothing. I guess I'll try all these suggestions and then take the motor out. Seems as though there is 2 problems. One is no power at switches currently and the other is why the motor wont move when I do put power to it. Stuck, fried, both, window track messed, etc. Thanks Mystery Train. I read all your other posts and hoped you would give your detailed instructions. Very nice. Even though motors rarely fail, one would fail on me. I just hate working on door crap and windows

Thanks again, more to come....

[rusnak]

dang, hate to admit defeat.....

check one last thing, put all fuses and relays back in, then hold driver's side switch in on position, and rotate key slowly from off to ignition on.

[Mysterytrain]

Rusnak..that drawing is great but real different from the little relay harness that I attempted to describe. The number on the harness that I'm refering to is 911-612-147-01. I don't have it installed yet so I have created a drawing of it. The harness is about 30" long and has a relay socket on each end. One of the sockets has four leads coming of its end of the harness, These leads are attached to the fuse panel along with the relay socket. Red/black goes to an always hot connection, red/white to an ignition switched connection. Brown goes to ground and the black wire goes to the power windows fuse. Down on the other end of the harness there is another relay socket and a long brown lead. The socket mounts behind the instrument cluster and the long brown lead is connected to the driver's side door jam switch. When the door is open the relay is activated and powers the windows when the igniton is turned off.

Back to your problem...pin 30 is hot. Its always hot on both relays, as is pin 86 on the convenience relay only! Pin 86 on the fuse panel relay is only hot when the igniton switch is on. Now. if you remove the fuse panel relay and pin 87 is still hot then there are two possiblities.. the driver's door is open and has activated the convenience relay or.... the contacts on the convenience have fused together. The second scenerio would allow the power windows to operate at all times.
Hope the drawing helps:

[Mysterytrain]

anyone have a number for the power window relay that is shown in the schematic rusnak posted? It appear to have a little RC circuit to maintain power

[clevy70911T]

Thx again for the help, but I'm going to have to bite the bullet and take the motor out and test it. I'm still not getting power to the switches in any circumstance and when I apply direct power to switch or motor still get nothing. As far as the convienience relay, I'm not sure if I have one yet. I see a few relays behind the instruments, but they are tall rectangle ones and I assume the one I'm looking for is round too. I also need to do a bunch of continuity checks to see what goes where. My fuse 21 is empty. The alarm system and amp is wired in somewhere from 17-20. I have alot of work 2 do and the 2 thing I dislike the most is inside door stuff and electrical troubleshooting.
Since this seems to be more than one problem, I need to focus on getting the timing belt changed on the 325ix and worry about the 911 after that. Hopefully early next week. I'll be asking more questions then too. Thanks again all!!!!!

[rusnak]

The tall rectangle relays behind the oil pressure gauge are the turn signal and the buzzer.

I'm still not sure what all of the symptoms are. But if you have no power to the switches, then why are you suspicious of the motors? The only things between the battery and the switches are the key, the power window relay, and the fuse box1, if I'm reading this diagram right.

Since you have intermittent problems, I'd suspect the switch first, then the relay. If you're feeling gutsy, you should swich out a known good relay for the power window relay. Then change the key switch if that doesn't work. Then check for shorts near the battery and move your way outward.

[kepperly]

Scott,
I see you don't listen very well and are of the pessimistic type. Do as I suggested and replace the switches first, save some money bye doing the cheapest fix first. Porsche over engineered most of the stuff they made but switches they bought outside. Like I said the mtrs very seldom fail.

Keith Epperly
87slant nose turbo look carrrea cabriolet

[clevy70911T]

It's not that I dont listen, it's I already tried 3 new switches and I now have 6 good switches. I dont routinly just start relacing things, but the switches were going to need replaced eventually anyway. Applying 12V directly to the motor, the motor should at least growl and it's does nothing. I feel that alone rules out the switches. Like I stated before, I need to take it all out and test it out of the door. I hope youre right, but right now it doesn't look like I'm going to get out of buying a new motor. You call that pessimism, I call it probability. But thanks for your suggestion and character dianosis.

[rusnak]

I'm pessimistic too. Both motors are bad? Did you test for resistance? I mean, it's more likely to be the window regs than both motors. Doesn't it tell you something when there is no power to the switch?

[clevy70911T]

Yes, I hope it is the regulators and doubt that both motors failed at the same time. Somethings fishy and I'll figure it out sooner or later. Since In have at around an hour left on the BMW, I plan on getting back to the window problem later today.