Power window and sunroof issues - 1996 850 GLT

[npexcept]

I would follow it down

[Didntchaknow]

Long time no see! Life came up again, but luckily these past two weeks I had a lot of time to seriously dig further into this issue.

For those who are curious or might have the same issue, there's some good news - my windows and sunroof work once again!

I went thru a lot of trial and error in order to find the issue, but luckily, the graphics and info provided here proved to be very helpful.

First things first: I worked to isolate the short further. Since I decided to follow the power down, I started at the fuse box, to attempt to see if any of the connectors/fuses were loose or damaged visible. (If you're doing this, don't start here - start in the center console)

The job of pulling out the fuse box is a hassle and more than a little painful to put back together. If yours is anything like mine, it's absolutely falling apart. I got to the underside of the wiring of the circuit breaker and wasn't able to identify any breaks in the wire themselves, and after fishing around enough to pull the lower relays up and follow the connections, didn't see anything there either. Finally pulled the fuses themselves, and pulled up the fuse box face. If you're wondering how hot the circuit breaker was getting - you can see the discoloration on the plastic face of the fuse box, AND on the copper below.




Unfortunately for me, the short wasn't in or near the fuse box. I messed around a bit with my short finder, and it wasn't sending any signal further than the fuse box, so I set that aside.

This narrowed down the short location to below the fuse box and above the master switch - so, likely either in the dash or in the center console.

To isolate further, I decided to pull the C/CK connector to see if the short fell above or below that. I reaaallly didn't want to take apart the dash, so I aimed to try everything else before that, so c/CK it is. This is a 12-pin connector that is located just underneath the plastic dish that contains the OBDII thingy and the cigarette lighter. The best way to reach this connector is to remove the entire center console (which is surprisingly uncomplicated with a helpful YouTube video or two). After removing the center console and the connector, I turned the car on again to see if the circuit breaker was still overheating - here's where it started to look up - no overheating!

That means, the short was somewhere in the center console wiring, not the dash (thank goodness).

Here's the center console removed from the car -The wiring that we're looking at here is the fat solid blue wire, going from the connector to the relay to the bottom of the master switch. The grey connector at the right most side of the picture, hidden slightly behind the console plastic, is the C/CK 12-pin connector.



Using the short finder, I followed the signal to a small splice just before the master switch. This is a factory splice - a little piece of red wrap on the blue wire that controls all the window functions. If I had to guess, this had a some point managed to get some water in the wiring or the splice might have decomposed to the point of touching another wire and shorting. Although, here's where I gave a big old shrug, because at this point I had been working on this for who knows how long. Instead of cutting and splicing the wire again and worrying about the splice failing in the future, I decided to just purchase a new master switch. Especially considering my old master switch has a switch missing, I bit the bullet and got a new one (wiring and fuse included) for about $80.

Yesterday I plugged the new switch right into the C/CK connector to see if it would work. And - joy! - the windows work!

I spent part of today putting the center console back together with the new wiring and switch, and I'll be finishing it up tomorrow.

Very excited to have them working again! Hopefully they continue to function correctly for a good long while.

If anyone runs into this issue in the future - best of luck to you! Start at the center console haha.

[npexcept]

@Didntchaknow glad to hear it finally works again!
80 bucks sounds like a bargain!

I'm also super busy since weeks (months?) with my work and havent made any progress with my 03' XC90.
Stupid oil leak is preventing it from passing road safety check (TÜV here in germany).
It's the seal between crank and transmission, so not easy to fix (in a garage without a lift).
Shop did qoute my firstborn for this job.