The motor limit switch is bad....been there...done that. I played with it for 2 months...changed gears and the whole thing....
The armature shaft is spring loaded and allowed to move back and forth. It turns or rotates to move the headlight up or down, once the headlight meets it's stopping point the armature tries to continue moving the headlight, because the headlight can no longer move the worm gear causes the armature to move forward or backward, attached to the shaft is a set of contacts, when the shaft travels enough in one direction it causes the contact on the shaft to hit the contact on the motor housing making the armature stop turning, this is called the limit switch.
When the limit switch quits working the armature continues to try to lift or close the headlight after it hits the stopping point. Something has to give so the gears are made to give after reaching a level of torque before the motor burns out.
So best bet is to replace the motor, else you will continue to eat up gears.
