88 Fiero - driver's headlight works without issue. Passenger headlight powers down, but not up (if I raise it manually with the knob, then turn the headlights off, it goes down at the same rate as the drivers, but never goes up on it's own. But will power down every time). I looked through the headlight troubleshooting guides, but they only seem to cover both not working on the 87/88 models (I do see guides covering one or the other not working, but only for the 84/85/86 models).

Since it's going down without issue, that would seem to imply that the power, ground, and control module are OK, and the isolation relays in the older systems are now in the control module, correct? So this would appear to be a limit switch issue within the motor, right? EDIT - from what I'm reading now, it appears that the control module uses current sensing to stop the motor in the up and down positions, so I wouldn't have limit switches either...which only makes me even more confused, lol. The motor is NOT spinning when I turn the headlights on, so it doesn't appear to be a stripped gear either.

EDIT 2: I just went back out to play with it a bit, and found that if I manually twist the knob about 1/2 turn to begin raising the headlight, then turn on the headlights, both lights will raise all the way up without issue. I was able to get them both to power up and down a few times after, then it went back to the passenger side only powering down. If I again twist the knob, then turn on the headlights, it will raise on it's own every time (every time with manually twisting the knob).

Given that, is there a mechnical travel limiter somewhere in the assembly that needs to be adjusted, or perhaps there's a dead spot in the motor that's being hit in the full down position...me twisting the motor gets it off the dead spot, and momentum keeps it going after?

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1988 Piero Formula w/auto - stock for now
1996 Camaro Z28 w/6 speed
1965 International Scout 80 - rock crawler project

[This message has been edited by urbex (edited 07-17-2012).]

There are no limits in the 88 motors, they are just motors and nothing more. All control is by the module inside the finder.
The stop limits are the headlight assy.

My guess is either the FET in the module for that side is bad or poorly soldiered or the relay contacts located inside the module are dirty or the bushes in that motor are dirty or the spring on them is weak. (to many ORs there)
But first....
Since the motor always stops in the same place then down it could also be a dirty commutator in the motor.
You might try pulling the motor out and connecting it to 12v for 5 min. or less (not to long as they are not made for continuous running) and then reinstall and see if the problem goes away for a while. Is so you could then take the motor apart and sand the commutator with some very fine sandpaper to clean it up and check the bushes. If it's not the motor then you have to start looking at the module.
I suppose a slightly stripped gear could also jamb it a bit and cause a startup problem but not likely.

[This message has been edited by Dodgerunner (edited 07-17-2012).]

A combination of increased friction, bad brushes, and cracking rollers can add up to everything stopping. The rebuild is not so bad.

It's a long shot, but the easiest and cheapest. I am in the process of painting my 88. I've taken the headlight doors off several times for sanding, priming and painting. At one point I didn't have it lined up exactly and it was catching on the hood. Good luck.