By motor gear, you mean the one on the motor shaft, right?
The headlight mechanism has a gear drive that the motor gear meshes with. It was a plastic gear with a metal hub. The plastic cracks and jams the whole shebang. Happens all the time as the plastic reaches the end of its life.
This same born-to-fail gear is also used in both door window gear drives.
Vendors have solid brass replacement gears for the nylon/metal OEM piece. Often only noted as being for the doors, but it is a direct swap for the headlights, too.
Look into your gear drive assembly. Pretty sure you'll find the problem.
Larry
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