I have been having a problem with my driver's side headlight not opening the past couple of weeks. I replaced the plasic gear with the brass one well over a year ago and haven't had another problem until now. When I turn on the lights the driver's side doesn't move at all and has no noises. If I turn it up manually just a little and then turn the lights off and on again, it comes up just fine. After this, it goes up and down just fine and seems to work for a while (rest of day). After not using the headlights for a couple of days the problem returns. Any ideas would be greatly apprecieated.

Rusty

 

If the problem was with both I'd have said the light switch. If its just the drivers light It sounds like you have gear troubles aagin. The fact that it comes up after you've manually adjusted the gear position also fits.

Is the headlamp motor case still properly glued together? If that has come apart it may be letting the gear move in the mounting?

 

My case was not the one that is glued together. I believe it had screws holding it together. This is an early 2000.

 

Bang goes that idea then

You may have to strip it down again and have a look.

Another member posted this tip on how to check the motor. it may be worth atry before you strip it down

Another way to check the motor is as follows:
1. Unplug the connector just behind the headlight to disconnect the headlight from the car's electrical system.
2. Identify the 2 wires that control the motor. It's the Light Green/Dark Green on one headlight and Light Blue/Dark Blue on the other (i can't remember offhand which is which side, but the other 2 wires are the same color on both sides).
3. Get a +12V separate power source if you have one (or rig something up from the car's power).
4. Connect the Dark wire on the headlight side connector to Ground.
5. Now apply +12V to the headlight side connector's Light colored wire for a second or two. If you don't see or hear anything from that motor, then the motor is dead (possible broken wire internal to it). If it moves up then the problem is not in the motor, but more likely back at the control module.

The logic here is if you disconnect the headlight motor from the car and apply a direct +12V across the connector wires it should raise. The Control Module does just that except it keeps +12V on both wires and then switches the ground on the appropriate wire (hence applying +12V or -12V across the 2 wires) to raise or lower the headlight.

 

If you hear no noise at all from the headlight, the first thing to check would be the connections and if the motor is getting power.

 

Did you use Rodney Dickman's Gear or BFanker,the other ALL BRASS (no rubber insert) gear?

 

I don't know who made the gear, but it does have a rubber insert. It has been absolutely fine for well over a year. I just recently started having this new problem.

 

There was recently a case where the rubber of one of Rodney's gear's went bad. BFranks gears are all brass. Not sure the long term effect of running a solid gear without any shock protection. I am sure if it is Rodney gears, that he would send (maybe sell) you another rubber insert. The recent case was the first time Rodney had heard about his rubber insert failing.

 

hmm, I've got the exact same problem with my passenger light. I doupt it's the gears since it pops just like the drivers side when it works. I haven't listened for noise when it didn't work yet but will next time.

Are there some limit switches to control the power to the motor and cut power when the end of travel is reached? That was my first thought.

Peter

 

There is a headlight module, mounted under the passenger side headlight. It senses the current surge when the headlights hit the stops (up or down) and cuts power to the motor. It also reverses the polarity, so motor changes direction. It is this method of stopping the motor which allows the worm gear to put pressure on the plastic gear that causes our problems, since it stresses the plastic gear and utimately breaks it. I am told that this module rarely goes bad. It is real expensive also (near $200).

Have you replaced your gear? If not, then you are in the early stages of gear failure.
Here are the stages my "stripped gear" went through.

1) Problem with right headlight not popping up all the time, but light was on. You could ensure it always popped up by loosening the manual headlight **** a few turns before trying.

2) Took a long while but much later, then it would make a machine gun noise after closing for 4-5 seconds. This was obviously the stripped gear sound.

3) Things now got crazy. Sometimes my headlights would pop up when I just turned on my parking lights, but they would not be on.

4) Replaced right stripped plastic gear with brass one. Everything fine. I have left gear but did not put it in yet.

There is a solid state headlight module. It is expensive from the dealer (over $200). I am told these rarely go bad. It is located under your passenger side headlight. It works by sensing the high current when a headlight motor hits a stop and turns off power. That is the cause of the stripped gears, the metal worm gear trys to keep turning until the module turns it off, putting stress on the plastic gear. Oh, there is a rubber shock absorber piece that the motor drives the gear through, it usually goes bad also. Rodney Dickman includes new rubber piecies with his kit. Cost of kit is $90 for 2 gears, rubber piecies, gaskets, lube and if later year includes expoxy and braces (they are a little more $).
Here is the link for Rodney Dickman's kit:

http://www.rodneydickman.com/retail_new.html

choose "electrical" and scroll down to your year

It contains all pieces: brass gears, rubber shock absorbers, lube, gaskets, expoxy and braces for later years.

 

OK, I'm going to have to investigate mine further. It makes no bad sounds when it doesn't work yet.

Here's another one for you - is the external temp sensor circuit grounded uder the hood somewhere? It is reporting somewhat low temps which started about the same time as the headlight. Could these problems be related to a bad ground connection?

Peter

 

MassaRusty,
I have a similar problem on my couple every couple of weeks. I think it is due to lubrication on the headlight gear teeth. I replaced my passenger gear with a brass one a while back and noticed the problem almost right away. I didn't however, use the white lithium grease that was on the stock gear (I was lazy and used what I had in the garage). When my light doesn't open, I can tell that it power is being applied by the motor, but it just isn't opening.

The headlight was closed so tightly on the way down, that the motor can't break it loose on the way up. If I manually turn it half a turn, the electric motor will run it right up. I have been meaning to open it back up and replace the grease with the white grease, but it happens so infrequently that I forget about it.


When you replaced your gear, what kind of lubrication did you use on the new one?

 

The gear kit I have came with some pink lubrication in a little baggie. The lack of lubrication is the first thing that came to mind when it first happened. It sounds like MrPDJ and I have the exact same problem. I will probably pull it out and take a look at it when I get a chance.

Thanks

 

I relubricated my headlight gear last weekend with grease designed for worm gears (I used it on my garage door opener also.)

So far no problems. I'll have to wait a little longer to see if that was the real issue.

 

you might try Lubiplate "Aero". My garage door mechanic claims it is the only thing to use on worm drives.

White in color.

good luck

 

Jeez, I'm thoroughly confused now after reading this post.

I replaced the drivers side stripped plastic headlight gear approx. 8 months ago with the Rodney Dickman kit which also included the new T-brace. I really took my time and used all of the included grease for the worm gear. All was well with no problems whatsoever until recently when I too had the "headlight on but not flipping up problem". On the same darn drivers side too!

I took it to my local Chevy dealer and the normally reliable and trustworthy Vette mechanic there says my problem is a faulty "headlight motor control module". He says he's 100% sure and suggested that I order the part from Fred Beans to save some money. So that's what I did and I'm waiting delivery on that part but I'm concerned now that this part "rarely fails" as reported by others. That grease in the Dickman kit seemed like quality stuff and I used it all. I'll stay tuned to this thread and report my progress. Thanks everyone for all the info...and the confusing overload of factoids!

 

What is the part number of the headlight motor control module? I'm having trouble with both of mine raising now since I installed HID's. Sometimes they raise, sometimes they don't.

 

The GM part number given to me by the dealership is:
16523917
It appears to be correct according to Fredbeans.com.
I'm still waiting for mine to show up. I hope it works.
I'll keep forum members posted.

UPDATE: Hooray! My headlights now open and shut the way they are supposed to. The headlight motor control module came in and I decided to install it myself. It was a bit of a pain since the module is tucked in under the passenger headlight but there were no major complications. The part was pretty costly, considering it's just a module, but the price I paid from Fred Beans was alot cheaper than having the dealer supply and install the part. At least I now know that the drivers side motor gear I just replaced wasn't the problem. The passenger side motor is starting to feel loose but it still works so I won't replace that gear until it the door stops opening. Finally, something works out for me the way it is supposed to!

 

I have been dealing with this probelm intermittenly for quite a few months, but I finally got around to taking it apart again. It looked like it was a little light on lubricant, so I put a little more on. The other thing I noticed is that the main screw had a little play in it. I tightened up the adjustment thing on the opposite side from the manual **** to open the headlight. The screw may have been moving a little to the side and been getting jammed. I could have just been too litte lube as well. It has not reoccurred in the two days since I took it apart again, so I hope I am done with this.