Remove the door panel and check the wiring. Sometimes the wires lose connection somehow. If all looks good....its most likely that you need a new window motor. Could possibly be the window switch, but I doubt it. You can test the motor to see if its good by directly hooking it up to the battery.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!