96 Passat TDI window jerks upon closing

My 96 Passat TDI driver's window jerks when closing, as if it is still trying to roll up. This happenned before, and eventually quit working. The auto shop sai d they had tightened a bolt. We removed door panel (thx to MilesD & others), but could not figure out what to do next.

Any suggestions?

It sounds like a shorted wire at the harness where the wire go between the body & door.