Window regulator woes

[911buff]

The passenger window on my '91 C2 will not go up electrically, via the regulator motor. It lowers smoothly, however the motor continues to run, even though the window is bottomed out. Is the motor damaged? Since it winds down, I would think the motor is not the issue. Is there some kind of limit switch to tell it to stop? How does it know to stop? Any ideas? Thanks!

[gizmofixer]

Check your window switches (both of them are in the circuit).
This is a very common failure on these models.

[911buff]

Thanks for the advice. I have had problems before...a broken switch, which I replaced. This problem was also the switch but I did not suspect it because the window did go down, just not up. Previously it just stopped working all together. Easy diagnosis. When I pulled the "new" switch apart, one of the rockers was lying on its side, obiviously not making contact. Hense the "down" circuit worked when the "up" circuit did not. The switch is not of good quality and has to be re-engineered (that is how I kept the original switch working long after it broke the first time). Again, thanks for the advice.