I have a 1993 300D 2.5 Turbo. The front drivers side window works fine going down. Going up, it hits the top of the door frame, at the fully closed position and then thump, thump, thump. The motor should stop, but, it tries to keep going up. I lift my finger off the close button and it stops fine, but, I'm worried that the window will break or the motor or some other part will be damaged if I keep using it. It seems like the 'limit switch' is not engaging at the right point, or some tab or maybe gear tooth is broken? I'm trying to figure out where the 'limit switches' are that tell the window motor that the window is fully closed or fully open. Thank you, Richard