Power window relay

86911cab · 10-25-2016, 04:26 PM

1986 911 Cabriolet.
It seems that my electrical circuits differ from the Bentley diagrams. I'm guessing this is common.
Anyways, I have been working on getting everything working again. Wrapping up repairs on the fresh air blowers, finished repairs on the heater system and fixed issues with the wiper lever.
Now I am tackling the power windows and the washer system.
I have been having a problem with a draw on the battery when the ignition is off. While checking out the (behind the gauges) relays, I found that one of the relays is hot to the touch all the time, even with the ignition off. It clicks when I turn on the ignition. Bentley says it is the power window relay. Opened it up to find a large resistor near that area where it is hot. I'm thinking this may be the problem with the battery draw. I pulled the relay and my windows still work, and they have always worked with the ignition off. Is this right?
I'll get to the washer system gremlins later.

86 911 Targa · 10-25-2016, 04:45 PM

PM sent.

Gerry

darrin · 10-25-2016, 04:47 PM

do your interior lights work properly when you open both doors?

The relay keeps the window circuit "alive" after the engine's turned off until you open a door -- no trigger that the door's open and the circuit remains alive.

86911cab · 10-25-2016, 07:19 PM

Quote:

Originally Posted by darrin

do your interior lights work properly when you open both doors?

The relay keeps the window circuit "alive" after the engine's turned off until you open a door -- no trigger that the door's open and the circuit remains alive.

That may be the trouble. May have faulty door switches. That would explain the battery draw too. I'll check that tomorrow.

john walker's workshop · 10-26-2016, 04:01 AM

Yup, if the windows work after the door is opened, you will have a draw that will kill the battery in a few days. Either clean the contact point of the door switch, or better yet, get new ones.

famoroso · 10-26-2016, 04:13 AM

158 degree!!! "Fensterheber" window courtesy relay

49willard · 10-26-2016, 05:53 AM

Very helpful thread. I think that I may have the same issue (1986 Cab also!).
Thanks to all.

49willard · 10-27-2016, 11:52 AM

Well, I cleaned the contacts on both door switches. The interior light works properly, i.e. it lights when either or both doors open and shuts off with the doors closed. However, I can still work the power windows with doors open or closed. If I understand it correctly, with the door open and ignition off the power window should not work. Is that correct? I would think that if the door switches worked correctly for the interior light why would new door switches change the situation. Am I missing something?

86911cab · 06:52 PM

I have traced the black wire from fuse block 3, fuse 1 to the 86b contact of the power relay. GOOD
My interior lights work properly, door switches work also.

86911cab · 10-31-2016, 06:54 PM

Please refer to the new thread.
"Calling all electrical experts"