Rear window won't close

[steamship]

Originally Posted by HPsauce

Finding the cause of the obstruction will be the task, unless it's an actual faulty motor.
Given the unpleasant noises I've heard it does sound like a mechanical obstruction somewhere.

Rereading your original post again, and what others have said about how it detects an obstruction, it sounds like the steel cable used in the mechanism has started fraying and wrapping itself around the motor spindle. That will add to the pressure on the motor itself, and hence it thinking there is an obstruction, and backing off.

If you look at the last picture Johannes posted on the thread he linked to, showing the window mechanism, I suspect you'll find quite a bit of the cable around the yellow spindle.