'85 Headlight Problem

Please help me if you can. I recently replaced my p/s motor with a new one and initially the light worked fine for three days. My problem now is that I cant get it to stop running once its closed. I have to unplug the connector. I am thinking that there is a contact problem or something that would shut it off after it fully closes. The motor just continues to run.

The only problem I've had so far (knock on wood) with the lights on "The Beast" was solved by replacing the nylon bushings in the gear mechanisms.  I'm sure someone else has experienced the same issue you're having and be able to offer a solution.

The armature in the motors move fwd/aft as they turn, and hit the "limit". At that point, it is supposed to open a set of contacts, and kill the power to the motor in that direction.
Yours is either too loose inside(too much movement), or the contact switch is no being opened. Either way, it's not an external fix....the motor will have to be opened and repaired, or replaced.
btdt...several times...

Also...what has most likely happened is the gear(s) stripped...but that only happened because the motor is not shutting off when it should.
If the motor you put on is new, or one you bought from a company, then it needs to go back to them, and have them replace it. If it is a used one from another car, you can rebuild it yourself, if you have the patience. I've done mine about 3 times now, but one of the problems with mine is the magnets for the motors are not epoxied to the outer case like they should be. I've tried JB Weld, but, apparently, it don't work very well! So...after the headlights go up/down a few times, the magnets spin, and the motor quits.
Adams' Apple2009-03-20 19:52:50

i agree , its the motor....  you can rebuild it yourself or buy one . i would rebuild it   these motors arn;t cheep  just my opion every body has one