I have a 95- C-280. The drivers side door lock does not work at all. but the passenger side does. Any one have an idea what i can look for or what I need to get to repair it. Also the left rear window is in the up position. If you try to open it it sounds like glass being crushed up in the blender. What is that? There is a motor noise. Would it be the regulator?
IS it an easy fix?

All thoughts appreciated!