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See if you can gently pull the light open, if it opens there is an issue with the bushings or gears. If it feels solid I would try removing the motor from the headlight bucket but leave it plugged in. make sure you can move the headlight through its full range to eliminate the possibility of a mechanical jam. turn the headlight switch on so the motor turns its full rotation, then shut it off and reconnect the motor to the headlight bucket with the bucket in its fully closed position and recheck.
Probably some debris in the gears. Maybe gear damage. You have to take it apart, clean, repair any damage and lube the gears and reassemble. If you did bushings you can do this. Most likely its trash in the gears.
IIRC, there was a washer/bracket next to the motor that has a short arm with a hook on the end. I remember having having to check the other headlight to make sure I installed it in the right direction. I would think if it got installed facing the wrong direction it could bind the mechanism.
See if you can gently pull the light open, if it opens there is an issue with the bushings or gears. If it feels solid I would try removing the motor from the headlight bucket but leave it plugged in. make sure you can move the headlight through its full range to eliminate the possibility of a mechanical jam. turn the headlight switch on so the motor turns its full rotation, then shut it off and reconnect the motor to the headlight bucket with the bucket in its fully closed position and recheck.