Windows, central locking and sunroof dead?

[Ross]

Yesterday I worked on a car with these problems and found a simple solution.
The GM which controls all this is fed from the power protection relay which is next to it in the rear E-box.
Check for battery voltage at pin 6 of the socket it rests in, if none or low your problem could be a corroded factory splice in the wire harness. This splice lies in a large black tape wrapped bundle of red wires that dead ends right beneath the E-box. Unwind the yards of tape to find a connection of four red/gry stripe wires, two large, two smaller. One of them is the power feed for the pp relay.
The car I worked on had seen some water under the seat and this connection had corroded.
Cutting the bad ends and reconnecting them cured the problems.

The moral here is don't overlook the simple things and regarding electrical spend some time with the wiring diagram before diving in.

The car's owner had given up(and was offering the car for parts) after ripping half the car's interior apart and exchanging nearly every electrical component in the car.

[shogun]

Thanks Ross!
I would have thought the usual suspect fusible link could be the cause.

[genphreak]

Thanks Ross!
I would have thought the usual suspect fusible link could be the cause.

Yes- great post Ross!

In an e34, a blocked drain at the rear of the sunroof cassette (the casing containing the sunroof assembly) will cause rainwater to fill the cassette (esp if the roof doesn't close flush to the roof panel) and then the water will dribble (overflow) onto the roof lining. Depending on the angle the car is parked in, water tends to drain secretly down the rear pillar covers and then drip into the boot and/or the rear wheel arch which transfers the water to the floor where it will fill up the two lower sections under the rear seat and or in the rear footwells (where the carpet is so thick it will prevent you seeing it.

Check under your back seat to know for sure- taking a good look under the rear power distribution block and battery. All this can happen without any obvious signs... you have to hunt very carefully- unless you just wait for everything to stop working...

Any water here will be from this cause (or accidental spillage down the rear seat) and should be addressed through a thorught dry out (remove front seats and lift the carpet on a warm day.

Best to be safe rather than sorry if you have a sunroof!

[cammo]

i get this problem when my car is cold. door accurators dont work, windows dont work, sunroof dont work, the first two speeds on the wipers dont work. once the car is slightly warm. turn her off n back on n every thing works again. feels like the car has a mind of its own

[Ross]

Nope, it feels like an intermittant open circuit. Perhaps more than one.