augustxke

I just bought a 88 911 cab with 63,000 miles. The former owner said, on occasion, when the drivers window is down completely it will not go back up. He said he slams the door several times and then it will work. I have had the car for several days and used the window a number of times successfully until yesterday. The window did not respond, I slammed the door several times with no result, then walked away, came back and did it again and the window went up. The shop that did the ppi changed the switch. The passenger window moves faster and easier than the drivers window. My wife and I are planning on leaving for a week long driving vacation in the car in two weeks, what are your suggestions?

09mageec

Does the the motor sound like it is attempting to work, and is just getting stuck?


I am very new to these cars , however, if I remember correctly, I had heard something about lubing the rubber guides? Anyone else have any insight on this?

augustxke

There is no motor sound, It seems like there is no power to the motor.

Amber Gramps

The door are simply to get into. You can check for power at the motor. If it is getting 12-13v then replace the motor. If it is slower already then just go ahead and have the new motor in hand and replace it. Will likely solve both issues.

jennifer911

Slamming the door to restore operation and the fact that other window operates at a faster speed are symptoms that the soft carbon commutator brushes inside the power window motor are worn down past the limit of reliable operation.

Do to the car’s age and the fact that the driver’s window gets the most use you would expect to see this. As the brushes wear down they are pushed outward by coil springs to keep electrical contact with the motor’s commutator. When the brushes become worn to little nubs the springs are completely extended and have lost the ability to exert adequate pressure to maintain electrical contact. A good door slam, or pounding on the inner door panel with your fist (allows a brush that is not only worn out, but will also be gummed up in its slots with dirty black carbon dust) jiggles the brush enough that the last vestige of spring pressure temporally activates contact.

This is pretty common on other makes and models of other cars (I owned one). If you buy a rebuilt motor from AutoZone etc this is typically the only parts they replace. The motors are easy to open up to have a look, and if the replacement brushes are not sold by Porsche, don’t shell out Porsche prices for a new motor. Brushes for things power drills etc will be a close fit, the carbon is soft and can easily be sanded down to make a good fit.

augustxke

Thank you

gerry100

I'd Check the switches on the door. They break
The pass window on my '86 lowers slowly if at all using the driver door switch but goes right down using the pass door unit

They pop right out to swap
and test

Pavegeno928

Not discounting the window motor as the issue. Here is a tip. I keep two spare window switches in the '88 cab. They last a few years at best. Once the switch starts being finicky, you can maybe play with it to get it to work a few more times, but I just go ahead and replace it at that time and know the other is shortly behind. They are cheap. The Genuine Porsche ones seem to last longer. I typically lower and raise both windows from the driver's door switches every drive so they get lots of use. The single switch on the passenger side lasts quite a bit longer since I'm usually alone in the car.

Do you have an automatic power top? If so, I'd keep a spare switch for that also. Last time I needed one, they were on backorder. Also, make sure you have read the manual on how to work your automatic top should it fail. You need to have the emergency crank tool from the factory tool kit which should be with your car. If not, get it. The only failure I have had in 11 years of ownership was, of course, in the pouring rain with the top down and it wouldn't go up. I was able to get to cover after getting drenched. Even knowing how to do it and practicing it a time or two, it took some time to raise the top using the manual method from the owner's manual.

One more on the power top. It was finicky the first several years. Chased replacing a bunch of parts until I finally replaced the electronic module. In 11 years, I've had to replace the cruise control module, DME Module, and power top module. They are old and the soldering cracks. Here is the place for great service: http://www.ecudoctors.com/porsche-91...1984-1989.html

Here's my '88 with 144,xxx miles on her 29th birthday this week in front of the Factory.

Good luck and enjoy!

augustxke

The switch was replaced during the ppi.

Spyerx

Could be the motor, could be the regulator, could be the mechanism arm thing (that pushes the window up) just needs some lubrication. None are hard to do. The motor itself is easy to remove, pull the door panel and reach up in the speaker hole, 2 torx screws hold it in, be careful pulling it. You can remove the windings and clean the commutator and check the brushes.

Mine was doing something similar (well the slam to fix didn't do anything lol) but it ended up being the motor just being tired. I found a good used one here for maybe $50 or so and just swapped the motor.