Electrical sunroof issue?

[JSanders]

Hello, all!

The sunroof on my '87 911 slant nose Carrera stopped working intermittently in the past two weeks, and finally has stopped opening all together. I can hear the sunroof motor whine when I press the "close" side of the switch, but I hear nothing from the motor when I hit the "open" side of the switch, like it is not getting the power signal for the motor to open sunroof. This makes me think it is a switch/relay/ground issue, but I have no idea where I should start troubleshooting.

Would anybody be so kind as to point me in the right direction? A search yielded me many results related to repairing the sunroof cables, none of which seemed relevant to my problem.

Thanks,
- J

[gerakroo]

Probably one of the contacts on your switch is burned. This happens very often as the motor has no end switch or relay and takes all the load of the motor. Very easy to change. There's a a 4 pole connector on it.

[JSanders]

So I finally got around to poking around with a multimeter today. I'm getting power all the way to the sunroof motor on both the "open" and "close" wires, but the motor is still not responding to the open signal from the switch, which leads me to believe the motor is failing.

Anybody have any experience finding a replacement motor? Is it repairable? I'd rather not spend the $700 asking price for a new one if I can avoid it.

[wwest]

Originally Posted by JSanders

So I finally got around to poking around with a multimeter today. I'm getting power all the way to the sunroof motor on both the "open" and "close" wires, but the motor is still not responding to the open signal from the switch, which leads me to believe the motor is failing.

Anybody have any experience finding a replacement motor? Is it repairable? I'd rather not spend the $700 asking price for a new one if I can avoid it.

If the roof motor runs in one direction but not the other the switch is faulty.

Measure the voltage ACROSS the 2 motor power input wires, NOT with respect to ground.

[JSanders]

Copy that, I'll get a new switch ordered. Thanks for the help!

[JSanders]

Just thought I would post a follow up, replacing the sunroof switch did in fact fix my issue. Thanks again!