Hello everyone, as the title says I've got a headlight problem. When you turn turn the lights on they come on and flip up about halfway before they stop and don't go anymore. I've tried to find this particular problem online but I must be blind because I can't find it. By the way the car in question is a 1990 zr1 purchased 2 days ago I figured since its a light issue and not something specific (I don't think) to a zr1, I'd put it in the tech section. Thanks!

 

take a look 0n youtube they have a good video to fix them just raise your hood then turn them on till fixed cheap fix a hour or two per side.

 

A gear replacement could solve your issue imo

 

If its both headlights and they are doing the same thing I would suspect an electrical problem. The motors work independently of each other so I doubt the gears is the issue.

 

Yeah both headlights go up about half way and stop, they don't go down all the way either when they're shut off.

 

Are they opening and stay up with manual ****?

 

did you open the hood and try to open them

most likely just the pucks

does the motor run on for a few seconds

 

You need new bushings:

 

I had the same problem with just one headlight. I replaced the gears, pucks and motors and spent many hours trying to find the problem, nothing worked.

Finally the guy on feebay that rebuilds the motors had me send him my whole unit, he found a bent linkage piece and a slightly out of adjustment stop. He replaced the offending part and adjusted the stop and the headlight works flawlessly.

Being both of yours are doing the same thing I would think it might be electrical. Try applying 12v directly to the motor lead and see if works properly like that. If so it's probably electrical for sure. If not I'd say mechanical.

Rick

 

The headlights are controlled by current; just like the electric window motors. I believe the "body control module" is where the current sensing resistors/op-amp setup lives. The idea is that both motors will hit the stops about the same time. As the motor rotors lock, amperage/current increases and the body control module disconnects power. They do the same when opening and closing. The idea is that if the headlight doors loosen up when going over bumps, etc. they will always try to move in the direction in which they were "parked" to hold tension against the stops. Therefore, if either of the door actuating mechanisms get in a bind somehow, or the current sensor gets weak, it will cause power to be cut prematurely.

I'd start by investigating each headlight door to make sure everything moves smoothly. You'll likely discover one of them with issues. If you don't find it there, it could be the body control module.

Also, it could be a problem with one of the gears as others have suggested. If some of the teeth are chewed up, it can cause the motor to hang up and draw excessive current. However, in that case, the other headlight would probably still stroke all the way.

I'd bet its the body control module. Its the common point for both motors. You mentioned that they both stop at the same time so that would make sense to me.

You can have a similar problem if a connection is bad. The reduction of voltage translates to more current draw.

 

Bluz, my port side was binding and stopping half way but the starboard side was working fine. If I understood your post you stated if only one bound then both lights would stop opening?

Rick

 

Yes. That's usually correct. It depends on current and how quickly it increases in order to stop both headlight doors at about the same time. But I expect that is your problem. If you free up the mechanism, you'll probably solve the problem.

By the way, I discovered a unique lubricant I've been using on things like the headlight doors where a sticky liquid would attract and retain dirt and cause eventual failure. I live in the Seattle area and was talking to a friend of mine who works in Boeing research. They created a custom lube formula for airplanes that they've used at Boeing for years. They finally released it to market. It's called Boe Shield. It goes on wet and then dries. Its a super lubricant and protectant. I've been using it on my motorcycle chain as well. If you Google it, you can find somewhere to order it. It isn't cheap but you don't use much either. I've used it in all sorts of places on my Corvette. It has been amazing how well it works and that it doesn't get grimy from dirt. For instance, I coated my parking brake mechanism and the electric seat parts. They were both filthy and covered with pieces of carpet and dust. They've remained lubricated and haven't gotten dirty yet. The same goes with the wiper motors, HVAC fan, and the headlight doors.

Just thought you'd like to know about it.

 

May be the headlight control module but I would check the less expensive fixes first.

 

Here is the video we did on this a long time ago...

I would follow the instructions above on operating the motors with the crank to see if they do indeed go up. If they do you'll know for sure the issue is electrical and not the motor. On the other hand, the gears failing is very.... Very common and I've seen two bad motor gears on one car before.