2004 Chevrolet Corvette head lamp door

Good morning, doesn't seem related to door locks. This happens when I shut off lights or am using twilight feature where lights come on in my garage and automatically go off. The grinding happens when door is in the down position. When I say grinding it sounds like something isn't dis-engaging. I did see some grey dust on what I think is motor. What I think is drive motor is in front of manual operation knob where you can open and close doors manually, assume this is for emergency operation. I have not removed motor yet, appears to be 3 mounting screws and nuts. Assume some kind of gear mechanism drives linkage to headlamp door.

Hope this helps thanks