E30 Zone

The window comes down ok but can't activate the motor to go back up.
Have tried another good motor in the connection and that won't go up either. Have tried a good switch and that doesn't help.

Any ideas?

What's the car? I'll dig out the wiring diagrams for ya.

86 320i 2dr

I'm a complete novice with electrics, not sure I'll understand the diagram but certainly worth looking at. Thx

or in PDF format from here:
http://users.rcn.com/xmon/86%20Windows% ... indows.pdf

Uses exactly the same wiring to go down as to go up. Current just flows the other way around. So, if you're sure it is still powering down, and the window is not physically stuck, then it can only be the switch, or just possibly it's plug.

stick 12v straight into motor see if it works then, most likely a dodgy switch

Thx for the advice.

I've changed the swithces around for one's that work ok. The switches are illuminated ok. When depressed the illumination goes out.

When the "down" is depressed the window goes down ok. When the "up" is depressed there's absolutely nothing, not the slightest noise. The motor does not even try to do anything. I've tried a new motor, without load and this will only go down too.

The plug connection looks ok. Should I strip it down and rewire anyway?

Mike

PS Sunroof works ok too.

Each switch has two seperate wires to earth (brown wires). These wires are the only part of the wiring which is not common to up and down. The relevant one of these must be faulty.

Cheers Brian, something to try tomorrow.

Mike

Have tried stripping the plug connection and rewiring, still no good.

The brown wires all look intact and ok.

How easy is it to wire in a complete new switch?
The car is being prepped for racing so it doesn't need to be cosmetically fantastic. It just needs to work.
If it's possible, any idea of what I need and how to do it?
Thx for your help guys.

Mike

Try shorting the two brown wires together near the switch.

Brian, just tried it ...... still no good.

I was going to suggest that your moror has a broken brush or something, that disconnects when it reverses, but , looking back to your OP, I see you've tried another motor.
In my toolkit, I have a 12V 5W lamp connected to a couple of bits of thin flexible wire. I've found it to be a usefull tool on several occasions.
If you can make up something like this, then disconnect the motor plug from the socket in the door, push the bared ends of the wires into the sockets of the connector, and plug it back together again, so that the lamp is in parallel with the motor. Then try the switch each way and see if the lamp lights up.
You could try it with just the bulb connected in place of the motor first as another test.