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headlights go up when turned off (with new gears)

15K views 32 replies 4 participants last post by  Junkman2008 
#1 · (Edited)
#2 ·
... Could this be a headlight control module, replay, or bad ground issue, or could I have put it back together wrong (left out parts, etc...)? I hope someone can help me figure this out! Thank you!
Bingo, fixed it for ya'. :thumbsup:

Okay, let me guess. You made the first cardinal sin that I tell guys never to do, which is you took both headlights apart at the same time, correct?
 
#4 · (Edited)
That depends. I need to try and see what you're seeing through posting. Hopefully I can get a clear picture that way. If not, we'll need to talk on the phone.

WARNING: Before you do ANY more work on the lights, take the following precaution. Manually raise the headlights and then unplug the gray power harness that controls the headlight motors, located just behind the headlights.



Failure to do this when working inside the cavity of your headlights can result in a very nasty hand injury. Even if the car is turned off with the keys removed, the headlights WILL CLOSE AUTOMATICALLY AFTER 15 MINUTES. This is BY DESIGN to save the battery if you accidentally leave something powered up in the car. Do NOT work on your headlights without doing this first. You've been warned!

The very first thing that I need to know is whether or not you have HID's. Answer me that. The second thing I want you to check for are the bump stops. There are 4 of them per headlight. Look at the pictures below.





Make sure that all 8 of yours are present. If they are, pull each one off and flip it over. The headlights will not work correctly if these bump stops are worn or missing.

If everything is still not working, move to the headlight module under the passenger's side headlight assembly (pay no attention to the text in the picture).



COMPLETELY unplug BOTH connectors that plug into that module. Then plug the connectors back in again. Make SURE that they are fully seated.

If one of those things does not fix the problem, we'll go from there.
 
#5 ·
Since your buckets operate normally while the engine is running perhaps you simply have a weak battery. Have your battery checked and replaced if needed. Weak batteries often make weird things happen with these cars, so since they close while the car is running, a weak battery would make sense since the computer doesnt get the correct voltage reported from the lights thinking a light is bad and keeping the buckets up. I hope it's a simple as that, good luck.
 
#6 ·
You would be 100% correct... if he has HID's. That's why I asked. If he doesn't, I have never seen a weak battery cause this issue with stock lights. The may go up and down slower, but not go one way and not the other. If there is enough juice to open them, there's enough juice to close them.
 
#9 · (Edited)
Just an FYI, you need to check back a LOT quicker to your threads. If a person waits 2 months to respond, I get board and move on.

Two questions. How did you know what fuses to check if you don't have the service manual? Two, your overall problem could very well be the multifunction switch. A Tech II could easily verify that.
 
#12 ·
Hi Junkman2008...

I do apologize for the lapse in my response, but an unforeseen event caused me to be unable to deal with my car until now. I very much appreciate any advice you can give me to fix this issue.

To answer your questions, the fuses I checked were under the hood, and the plastic cover indicated which fuses where for the fog lights. I have checked every fuse under the hood and in the passenger foot well with a test light, and they are all good. I was not sure if there was a known relation of the fogs lights not working intermittently and my headlight issue.
That's why you need the service manual. You can't trouble-shoot electrical problems with this car unless you know for a fact, what is connected to what. You don't know the history of your car OR the technical ability of the previous owners. I seen some hack-ass repairs done to these cars by people who couldn't afford them or people who didn't car because they were going to sell it. You could be a victim of both so you need the service manual so that you can check things out properly.

One thing that you cannot check out by looking at the fuses is the headlight control module, which is located on the passenger's side headlight. There's where the service manual pays for itself if you know how to read a schematic.

I am sorry for the dumb question, but what is a Tech II? I have a friend with a scanner that can pull codes. Is this the same thing?
Not even close. A Tech II is a diagnostic tool capable of reading data about the car directly from the on-board computers. Data like misfires and idle rate, cam position and host of other stuff. The Tech II can send commands such as raising a headlight and lowering it. It is the tool that GM technicians use to trouble-shoot problems with your car, IF they know what they are doing.

I thought at one point that the multifunction switch may be causing the issue of the lights going up instead of down, but from what I read, the multifunction switch is completely bypassed electrically when the twilight setting is set to "on", so it should not affect the headlights from closing properly. Do you know if this is correct or not? Also, I have done countless hours of searching, and I cannot find anyone with this same problem. Of course, I find many people that have issues with the lights not going down, but no one stating that they go up when turned off.
With all that said, I'm going to send you right back to the work you did on the headlights. As I posted earlier, the bump stops can easily affect this problem. You never did address that suggestion that I posted months ago. Did you follow that advice? Also, as Vettmann17 posted, now I'm curious about the battery in your car. Exactly who's battery is in your car and what are the CCA and the RC values?

As you mentioned before, if one of the lights were burned out, the bucket would remain open when turned off.
Where did I say that? I don't remember saying that???


If there was a short in the bulb itself, would that cause the buckets to stay open?
The bulbs don't have anything to do with the bucket operation.

Do you know if ONE of the bulbs were burned out, would it cause BOTH buckets to stay open or just the ONE bucket with the bulb out? I just cant seem to figure out what would make the motor run in reverse like this, and I hope that you can help me figure this out! Thank you in advance!
Answered above. Now YOU need to make sure that you answer EVERY question that I asked in my post. So before you hit the post button, ensure that EVERY question is answered.
 
#20 ·
The CCA is 650. I had mentioned it on my 5/8/13 post. I was told that the car needed a battery rated at 600 or above when I bought it.
Finally, some information that helps. They lied to you. The battery needs to be 700 CCA's and 120 RC. You have the wrong battery in your car. I thought so when I heard that crappy name brand. What you should have is an AC Delco Professional 78-6YR. I've seen them online for as cheap as $112.



The battery is more than capable of causing weird crap to happen in these cars, especially intermittent stuff. If your alternator is charging correctly, the first thing I would do is get the right battery installed. You can have your alternator tested at various places but I use a Solar BA7 (NOT the BA5), battery/system tester to make sure that everything is working/charging correctly.
 
#22 ·
Go get a load test and see if it holds. They are BS'ing you about the importance of the RC value because these cars have a slight draw even when they are not being driven. Test your alternator and then the battery. Let's see if it is holding up to snuff. There are a bunch of threads that talk about the battery values but the best thing that you can do is go to a dealership and have them give to you in writing that the battery you have is NOT made for your car. If you are going to buy the battery from the dealer, they'll be more than happy to give that to you in writing.

Lastly, update your profile so that it shows the YEAR of your car under your name to the left side of the screen.
 
#24 ·
I'm going to do you one better. Read the description below and follow along with the attached PDF documents (2).



Headlight Doors Circuit Description

When the headlamp switch is turned to the HEAD position, battery voltage is applied to the headlamp opening door actuator control module through CKT 103. The LH head lamp door opens when battery voltage is applied to the LH headlamp opening door assembly through CKT 576 and ground is applied to CKT 577. The RH headlamp door opens when battery voltage is applied to the RH headlamp opening door assembly through CKT 578 and ground is applied to CKT 579. When the headlamp switch is moved to the OFF position, battery voltage is applied to the headlamp opening door actuator control module through CKT 306. The LH headlamp door closes when battery voltage is applied to the LH headlamp opening door assembly through CKT 577 and ground is applied to CKT 576. The RH headlamp door closes when battery voltage is applied to the RH headlamp opening door assembly through CKT 579 and ground is applied to CKT 578. Battery voltage is constantly applied to the headlamp opening door actuator control module from the HDLP MOT L MiniFuse® #4 (CKT 2940) and from the HDLP MOT R, MiniFuse #3 (CKT 3040). The headlamp opening door actuator control module is grounded by CKT 150 through Splice Pack #100 to G102.
 

Attachments

#27 ·
First, thank you so much for taking the time to post this information.

I am far from an expert, so please correct me if I am wrong...Based on what you sent me, the open versus close functions are controlled by a reverse in polarity. What I still do not understand is what is confusing the module into NOT switching the polarity intermittently when I turn the lights off, causing them to re-open instead of close. I know that I have said this before, but I want to make it clear that my issue is NOT that they wont close intermittently, but they are staying up because the motors are running in the up direction instead of down, hence they are staying up. For example, with the engine running and the lights on and open, I can manually lower the buckets a few inches, and then when I turn the car off, they open fully, instead of going down. If I sit in the car when they are behaving like this, I can toggle the twilight switch or the headlight switch on and off, and they will eventually start working properly again. When I dont have time to play with them like this, I will drive around and when I turn off the car, they will work properly sometimes, and not other times. PLEASE confirm that we are on the same page, as others I explain this issue to are not understanding what I am describing.
I understand exactly what your lights are doing. I also know that this type of behavior is very typical of worn bump stops. That's what I suggested earlier in this thread and that's what Paul (C4C5Specialist), suggested on CAC's forum. Paul is a world class GM technician. He's the E.F. Hutton of Corvette knowledge. He's thinking the same thing I am. So let me make sure that you have done the following.

You have FIRST verified that BOTH headlights have 4 bump stops each. You have removed each bump stop, flipped it over and replaced it. Last of all, this problem was present BEFORE you replaced the headlight gears. Answer all 3 of those questions.

Now, as far as the battery issue is concerned, before I go to war with Walmart or have to spend $120 on a new battery, I need to be sure a new battery will fix this problem. As far as I understand, the CCA rating only applies to starting the car, and the RC rating is how long the battery will run the car if the alternator stops working. Otherwise, the alternator charges the battery while the car is running which supplies a 12 volt current to the accessories of the car. I called the battery manufacturer again to question if this is the incorrect battery for my car, and when I explained to them my issue, they stated that they have sold 1000's of batteries for this car and have never had any complaints similar to my issue. Please understand that I am not questioning your conclusion that the AC/Delco battery will fix my issue, but I need to make sure before I try to get my money back or put out additional money for a new battery.
Whether or not the battery will fix the problem is not the issue. The issue is, you have the WRONG battery in your car according to what GM recommends. So if it will fix the problem or not still does not address the fact that you are running the wrong battery. You at least need to have the correct battery in the car just so you can eliminate it from the equation and any future issues.

Also, I have asked this question several times and no one seems to have the answer...Is the headlight switch completely bypassed when the twilight is set to "on" or does it still have an affect on the headlight system? If it is bypassed, then at least I can rule out the switch causing the problem.
Here's how you verify that the Multifunction Turn Signal Lever is eliminated when the Twilight Sentinel is engaged. Turn the Twilight Sentinel ON while parked in a dark place or at night. The headlights should raise. Next, turn the Multifunction Turn Signal Lever to the full on position. Then, either drive the car into direct sunlight or shine a bright light into the Twilight Sentinel, located on top the dash pad. If the lights go out and the buckets drop, guess what you have just proven? Easy as pie.

Lastly, can the headlight control module cause this malfunction?
It has been known to cause various issues, this one in particular would not surprise me. Basically, they can go bad but are not a very high fail rate part. You can only test one with a scan tool like the Tech II.

I see the BCM on the chart you sent me on the right side of the page. Is this the BCM in the passenger footwell or is this the headlight control module?
The BCM stands for "Body Control Module". It is located in the passenger's footwell area behind a close out panel.



The headlight control module is located on the frame of the passenger's side headlight, just below the actual headlight itself.



Also, did you have a chance to review the codes I pulled and posted last week? Do you think they are related to my issue?
No. According to the service manual, this is a normal software function as long as the DTCs have a history status upon ignition cycling. No repair attempts should be made. Yours are showing history (H).

I am sorry for the long post, but I am just getting frustrated that I am still dealing with this issue (and a 8 month old pregnant wife!) Again, I very much appreciate your help and look forward to your response.
No problem.
 
#33 ·
No, I mean the BCM (Body Control Module) in the passenger footwell. It is on the schematic you sent me on the right side. I was just wondering what part it played in the headlight system and if it could cause this issue.
My bad, I've been working on too many issues today. The description of the circuit I gave you explains everything about the BUCKETS. You should refer to it. There's a different document for the electrical part of the circuit.

Also, what do you think about the test I did with the buckets removed? Does this rule out any mechanical error (bumper stops, bucket alignment)?
No. That test tell me nothing.

I asked this question a few times earlier in my post, and no one has answered it. Does my car have a feature where if one of the bulbs are blown out, will the headlights open or stay open to warn the driver to change the bulb? The only reason I ask is because if this feature exists, it is doing the exact same thing that my headlight are doing, except for the fact that the bulbs are good. In that case, is there a possibility that the headlights are sending a false signal to the computer to cause this same thing to happen?
If a turn signal or running light bulb blows, the lights on that side of the car will begin to hyperflash (flash very rapidly when you use the turn signal). The headlights don't do anything. So no, the car is not trying to send you smoke signals. That's what the DTC's are for.
 
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