86 headlight motor wont stop trying to spin?

So, two years ago the motor in the passenger side head lamp motor assembly was having some problems.(my father was the owner of the car at the time) I, not knowing what the problem was just left the light up, which looks hideous with only one up.  After having the car a few months i decided it had to be fixed.  I plugged the motor in and when it started rotating to close it got all the way closed and the motor kept trying to spin, like something wasnt allowing it to stop.  Now, not having a vast knowledge of such a problem i looked into a rebuild kit thinking it was a problem with the gears being warn and not being able to grip each other any longer.  I got the rebuild kit, followed a tutorial, and got it all done.  After plugging it in i had the same problem and because the motor kept spinning the gears they just broke apart and the light was just floating with no resistance... AWESOME!

fast forward, i bought an entire motor assembly from ecklers and installed it.  But, much to my dismay i had the exact problem... I'v looked into headlight motor relays?  Anyone ever had this problem or know if a new relay will fix the problem?  I want to rip my hair out with frustration...
thanks guys, this was my first post. 

Welcome to C4VR!!!

May very well be a stuck relay. The design of the motors is to allow voltage until the gears reach the end of travel in either direction. Once at the end of travel, the armature itself moves, and either makes or breaks contact with a set of points, thus opening/closing the relay circuit.
Worn bushings can cause this, as can worn gears, mis-adjusted gear travel, or even grease that has gotten hard.
Since you changed the motor assy, and had the exact same issue, I'd suspect the relay is stuck, but there may also be a short in the wiring. Replacing the relay would be the quickest thing to do.

Just be careful if replacing the relay to follow the exact instructions. There is a very specific sequence to disconnect the battery, install the relay, etc. and if not followed it will burn out the relay or the motor. Instructions should come with the new relay.

i know when i had them out on my 90 i went crazy try to reinstall them to get them to work right. found out that you have to open them fully before you connect them. was that is done and units are plugged back and battery reconnected they worked great. the open all the way position is the adjusting mode.