joecar

Good job

you make this thread an excellent source of information.

edit: fixed typo.

wssix99

iTrader: (5)

I can't take any credit for this one. This fix is all over the 3rd gen forums and Corvette forums. (The older cars use a similar module and the older Corvettes use the same part.) We're just the "new kids on the block" for this part and this problem. lol

wssix99

iTrader: (5)

It's too easy for a write-up. I probably could have taken pictures but wanted to experiment with the re-sealing. So - maybe the next person can take some nicer shots of the full disassembly/reassembly.

The process is easy:
1) Remove the module.
2) Pry the back cover off with a screw driver. The board will fall right out.
3) Scrape the old sealant off the body and cover.
4) Re-solder the joints circled above.
5) Drop the repaired board back in the cover.
6) Fill the channel in the cover with sealant, just shy of the top lip. (Either with a butyl sealant, dum-dum, rope caulk, or RTV.)
7) Snap the rear cover back on, wipe off any oozing sealant, and let cure with the module sitting on the cover. (So, the excess sealant doesn't drip on to the board.)
8) Reinstall the module.


I didn't want to drop money on butyl sealant or rope caulk (that's what the OEM sealant looked like) so I used some black RTV that I had laying around and it seems to have done smashingly well.

Everything is hooked back up, the headlights work normally, and hopefully you all will never hear me speak of this intermittent issue again.

wssix99

iTrader: (5)

After reading through the other older cars' forums and from my experience with solder joint cracking on other parts of this car (and other cars I own) my expectation of this problem is not a matter of "if" it will happen to Firebird owners, but "when."

I'll bet that other module you purchased had the same issue with the cracked joints.

My badly cracked solder joint (the one I could see separate under magnification when I wiggled the attached pin) was the "headlights on" input. So, the module couldn't "tell" when my headlights were on, or not.

bleepster

iTrader: (2)

Cheerio my good chap - cheerio



thanks. I may tinker this weekend

samerickson89

iTrader: (1)

Anyone know what years/submodels have the same headlight harness as a 99 Trans Am? Wanna get one from the junkyard, but they charge for entry and when checking the inventory on their website I'm not sure which ones will have the harness I need.

wssix99

iTrader: (5)

What's your problem? You can get the connector parts and terminals new.

The harness that connects to the headlights on a firebird is integral to the headlight door motor and you get a new harness with every reman or new door motor.

samerickson89

iTrader: (1)

PO tried wiring up some aftermarket lights and made a real mess of it. Some old wires are cut, some he left the old wires and sockets just dangling there, some are even burnt. Was hoping I could just replace the whole harness, but if new connectors and terminals are the way to go then I'll just do that.

wssix99

iTrader: (5)

With the age of the car, the wires getting brittle and a little charred is normal-ish. I just had to replace my harnesses for some aftermarket bulbs as the stockers were a little too short and encouraging some of the insulation to crack.

The wiring and connectors to do this will run you about $50. The proper tools you need will run you $125-$250 depending on what kind of deals you can find on used tools.

^ If you don't doo a lot of wiring/harness work, this may not be a worth-while investment as two new headlight door motors will come with new harnesses, will cost you less overall, and should give you more longevity on the motors/gears in the motors.

Another downside is that these tools will are only 1/3 of what you need to do all the harness that you will come across on the car.

sherbin18

Hi All-

Last night I had a strange headlight problem. When I turned on the lights, the left side came up (I replaced the motor gear about 6 months ago). But the passenger side didn't.

I checked the lights themselves, and they were lit up.

So, I remembered reading somewhere that the healight motors are fused and each is on a seperate fuse. I checked the fuses and they seemed fine. I pulled out the working fuse and put it in the nonworking and both headlights didn't come up. So, I put the fuse back in the driver side and it worked again.

I turned the other fuse around and put it back in the slot, turned on the headlights and the non working headlight worked. Beats the s out of me. There must have been some muck in the fuse socket.

Tried it again this morning and seems to be working.

My only question is, should I put dielectric grease in the fuse holder? I use it when replacing light bulbs and makes replacement much easier. I wonder if it will cut down on corrosion in the fuse holder?

Thanx. Steve.

sherbin18

Well, I'll try again.

The problem came back. Tried the same solution. Didn't work. Took the headlight cover and cowl off, massaged the plug connector, light worked again.

I'll probably take everything apart and use the dielectric grease. Can't hurt, will probably help.

UM Rebel

Hello. I don't own a Firebird now but they have always been special to me. I bought one of the first 2nd generation Birds to roll off the assembly line. Drove it many years and many miles. Anyway, I now drive C5 Corvette and recently had headlight problem just like y'all have. Stripped plastic gears, replaced with brass. Headlight control module leaked in water and fried. I got a bit creative and built my own HCM. Thought some of you might be interested. I am pretty sure it will work on Fiirebirds also. Here's link to my post on the Corvette Forum.
https://www.corvetteforum.com/forums...ol-module.html

joecar

UM Rebel, good job

can you provide more info on that module...?

UM Rebel

Here is link to where I got them off eBay
http://www.ebay.com/itm/131776109221
It didn't come with any documentation but experimentally this is how it works

I'm going to call the side with 2 connectors "bottom"
Side with 3 connectors "top"

Connector on bottom left goes to ground
Connector at center top is the power circuit being switched
Connector at top left is normal closed
Connector at top right is normal open
When connector at bottom right is energized with 12 volts
relay switches momentarily to the normal open connector
then back to the normal closed.
The length of time it remains in the normal open is adjustable by
the screw above the bottom connectors.

I did not change the factory setting on the timer because it
was set perfectly for the time it takes my headlights to open/close.

Hope that made sense and helped.:

wssix99

iTrader: (5)

It won't work. You need to remove the corrosion from the pins.

wssix99

iTrader: (5)

I would be worried about using a timer-based circuit on these F-Bodies as I think it would stress the gears and stops more than the stock unit that senses the voltage changes at the stops and just cuts the circuit then.

Given the price of replacing a burned-out relay or even a used module (they are pretty common across all of GM's flip-headlight cars), I'm not sure building one's own saves a lot of money.

UM Rebel

Not so much about saving money. It was fun! It works! I didn't see the sense in replacing a 13 year old POS part with another 13 or older POS part. Didn't want to send Eckler $645 for their new part (which is likely a POS).

As far as the stress, it's the stress that causes the current draw which allegedly the HCM senses to shut off. Then you have to ask, why, if you disconnect the motor from the door mechanism then cycle the lights on /off the motors spin for a second and shut off. A timer maybe?

wssix99

iTrader: (5)

I think we are both speculating. The chipsets could have multiple functions, but I have not been able to find a datasheet/reference for them. (Having at least a timer so (in a failure mode) the motor doesn't spin infinitely would make sense.) Nor have I seen a key as to what the symbols in the schematic in Post 1838 mean.

My2000Z28

iTrader: (1)

Hey after a bunch of searching, all I got was that the information is in this sticky. Unfortunately there are 1800+ posts all about different headlight problems. Maybe an edit is in order? Could you put all the important info if the different major issues that arise at the beginning? My headlight is dim and my high beam indicator light stays on. My solution is in here but it's a needle in a haystack

Probably none of your fault, all my search hits have been coming up with people with my exact problem being told "here it's in the sticky".....

wssix99

iTrader: (5)

Great idea. We're looking for volunteers to take this on.

This is usually due to corrosion in the headlight motor connector or at the headlight bulb.

There was a bad batch of bulbs on the market that also caused this - you may try switching your left/right bulbs as a first step to isolate that problem.

Does your highbeam switch "click" when you turn the highbeams on/off?