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Hello
greetings from Italy. I recently bought a 91 conv, and the headlights are giving me problems. When I turn the switch on the dash...sometimes they work perfectly, sometimes just the pass side will rise and very rarely, nothing happens. The light will come on...but the motors seem to be dead. If I turn the adjusting **** near the motors, the headlight will work immediately and everythings works for a dozen of times, and suddenly they stop working. When they work they work perfectly...
Where is the problem? On the control module or shall I rebuild the adjusting part of the headlight motors? Please help, in Italy nobody knows where to put hands.
Usually the drive bushings fail. When they do fail, they turn into powder. And because all the powder is still floating around in there, sometimes they will still work and the powder will drive the flip mechanism. And sometimes it won't. Most original drive bushings have failed at this point and need to be replaced.
People refer to them as drive bushings or pellets.
One other thing to try: Open the hood and operate the headlight switch so you can observe the black manual **** on top of the actuator. If the manual **** always spins when you actuate the switch but the headlights don't move (flip) consistently then this is very likely failed drive bushings as I mentioned previously. But if that manual **** is not spinning consistently, you might have a different problem.
When I turn the headlight switch on...the **** doesnt move. If I turn the adjusting ****...the headlight works for several time. But if I let the car standing in the garage for a day....the headlight doesnt work anymore. So I turn the ****....and the headlight turns The light is always on...it is just the headlight that doesnt turn. When it opens or closes...I dont hear strange noises...and the movement is very quick and strong
Not sure what the OP's problem is as it could be a couple of different things, so won't offer any conjecture here.
But, just as an aside, is there any reason why one couldn't fabricate their own bushings out of copper or brass or something a bit more sturdy so they don't crumble over time?
I know that they do make the brass gear.
Additionally, with so many owners swapping out their OEM headlights for the newer, much lighter LED ones these days, I think that'd take quite a bit of headlight weight itself out of the equation therefore alleviating much of the stress on the parts and allowing for a longer life of the vinyl bushings and gears, should one choose to continue running those.
If you get a voltage meter or probe light at the connector and if every time you turn it on/off it comes on then your motor can be on its way out
Yeah. This is good. If you don't have a volt meter, have someone turn on the light switch then tap on the motor with the handle of a screwdriver. If this makes it operate, I would say the motor failing. Maybe worn brushes. You can get inexpensive replacement motors online.
He says if he turns the ****, the doors open quickly, no noises, and will work several more times on their own. How can it be the "bushings"?
My 92 has one intermittent door. If I drive the car regularly, and use the headlights, both doors work fine. But occasionally the right door doesn't open. If I cycle the doors with the headlight switch rapidly, the right door will open.
In my case, I know that it is a sticky relay in the control module. My guess is that the OP has a module problem too. It's not the "bushings" if the doors open with the **** and work for a number of cycles.
then this is very likely failed drive bushings as I mentioned previously.
You also used the modifiers "Usually" and "very likely". I disagree with the bushing diagnosis because the motors run, the doors open manually, and continue to open and close for a number of cycles until the car sits overnight. This is why I used the word "bushings" and not "brushes".
Originally Posted by C4industries
I said maybe worn "brushes".
It's not the "brushes" either if the motors run when the OP turns the ****, which they do. Anecdotal: I've had a lot of these motors apart to replace the bushings. The brushes and commutators are always in like-new condition.
You're likely correct about that. That's what my problem was with similar symptoms.
Best advice I'd give about that specifically, and I'm ony speaking from my own experience, is try to buy a used Made In USA one from a forum member if you find this to be the cause.
I blew well over a hundred bucks for an imported new Chinese one since that's all that is available now and it fried after the first week. Was more hassle to return it than to just keep it as a spare and find someone who knows how to replace those resistors (or whatever they are) in there.
One other thing to try: Open the hood and operate the headlight switch so you can observe the black manual **** on top of the actuator. If the manual **** always spins when you actuate the switch but the headlights don't move (flip) consistently then this is very likely failed drive bushings as I mentioned previously. But if that manual **** is not spinning consistently, you might have a different problem.
The OP replied and said the manual **** is not spinning constantly. So he has a different problem.
Last edited by C4industries; Apr 2, 2026 at 11:59 PM.
It's not the "brushes" either if the motors run when the OP turns the ****, which they do.
No they don't! Not consistently. The OP said this:
Originally Posted by antonellomopar
When I turn the headlight switch on...the **** doesnt move. If I turn the adjusting ****...the headlight works for several time. But if I let the car standing in the garage for a day....the headlight doesnt work anymore. So I turn the ****....and the headlight turns.
Having similar issues. Lights flip up but motor will run after they flip up. **** spins freely when closed (can’t change the bulbs). When I disconnect the battery I noticed the motors run but headlights don’t flip up. Any ideas? Am I just replacing bushings and gears or should I just replace the Motors while I’m at it?
My passenger side light doesn’t close consistently. This morning the passenger side light closed half way. I turned the lights back on and then off and it closed, but I think I heard a grinding noise when it closed. At first I was thinking it was a switch problem, but now I think I need to rebuild the motor. Bushings were replace several years ago.
When I turn the headlight switch on...the **** doesnt move. If I turn the adjusting ****...the headlight works for several time. But if I let the car standing in the garage for a day....the headlight doesnt work anymore. So I turn the ****....and the headlight turns The light is always on...it is just the headlight that doesnt turn. When it opens or closes...I dont hear strange noises...and the movement is very quick and strong
At this point, here's what I would do: The next time the headlights fail to move, don't touch the ****. Carefully remove the wiring connector at the headlight without disturbing the headlight motor. Momentarily apply 12 volts directly to the pins that drive the motor (The polarity doesn't matter. If you switch polarity it reverses the direction of the motor) and see if the motor moves. If the motor does not move with 12 volts applied to it, then you have a problem with the motor. If the motor does move, your problem is "likely" with the controller. I would run this test before buying a new controller.
Having similar issues. Lights flip up but motor will run after they flip up. **** spins freely when closed (can’t change the bulbs). When I disconnect the battery I noticed the motors run but headlights don’t flip up. Any ideas? Am I just replacing bushings and gears or should I just replace the Motors while I’m at it?
Now this is "very likely" failed drive bushings. This is what happens when the bushings fail. I've had to replace bushings on 3 of the 7 C4s I currently own and they all behaved this way. BUT...Recently I was working on a friend's 88 Vette. One of the lights was doing this exact thing. I was "confident" that the problem was the bushings. But when we removed and disassembled the motor, the bushings were fine. What happened was the gear that drives the shaft for the flip mechanism came detached from the shaft. So the gear was just spinning freely on the shaft and there was no easy way to reattach it. So we needed to buy a replacement motor.
In your case, remove the motor and disassemble it. In my experience, "usually" they just require bushings.
Often, you don't know "for sure" until you run the tests and remove and inspect the parts.
Last edited by C4industries; Apr 4, 2026 at 01:03 AM.
headlights not working
