Driver power window dont work

[ChrisP911]

Ok go out to my car yesterday the window will not go down. The passenger side works from the driver side and passenger side.

test light getting power to the red wires.

I take the switch out of my other car still nothing. I disconnect the blue/black wire window goes down. I plug that wire in and disconnect the blue wire window goes up..

[fitchesbass]

I'm not tracking the entire troubleshooting flow.. but it sounds like a a bad switch. Take a switch from the passenger side and see if that works / fixes the problem.

Also can check for connectors slightly touching on the back of the switch. My car the previous owner looked like he had put larger connectors on, and I had to isolate them even more by wrapping the connector ends with some electrical tape.

Pretty sure the sunroof, and both windows are all on the same fuse. So if the passenger side works, the fuse shouldn't be the issue.



Good luck

[rick-l]

Here is how it is wired

Power Window Switch schematic

[rick-l]

what car is this?
where did the blue wire come from?

[ChrisP911]

1987 911

[rick-l]

That's right. I looked at the wrong page in the Bentley.

[rick-l]

Originally Posted by ChrisP911

I disconnect the blue/black wire window goes down. I plug that wire in and disconnect the blue wire window goes up.

Since those two wires go to the motor that makes no sense unless there is a connection to ground inside the motor or wiring to the motor. I think there is a thermal protector in the motor so you could let it cool off, disconnect it and check for a path to ground through the blue wires.

[rick-l]

Just out of curiosity does anyone know off hand what type of motor a power window has? Is it a permanent magnet or does it have a wound field (series/shunt)?

[DRACO A5OG]

Switch the Switches around to confirm it is not a bad switch or take an ohm reader to it.

[rick-l]

Originally Posted by DRACO A5OG

Switch the Switches around to confirm it is not a bad switch or take an ohm reader to it.

He already did that which is why I'd be leaning towards the motor. That is the magic one that works with only one wire connected.

[DRACO A5OG]

Oops my bad.

Time for a door panel removal, oh the joy

[ChrisP911]

the passenger side works fine with both switches i flip flopped several switches already. If it were a ground would both switches still work the passenger side.

[rick-l]

Originally Posted by ChrisP911

If it were a ground would both switches still work the passenger side.

A motor needs current flow to create a magnetic field and torque.

The blue and the blue/black wires should be the only electrical connection to the motor. If you disconnect one there is no path for current to flow, hence the mystery.

If you knew what type of DC motor it was it would be easier to speculate on the failure mode.

Measuring the resistance from the blue wires to chassis should be telling.