Firechicken86

iTrader: (1)

I have a 1986 firebird and have had some issues with the headlight and have heard a common issue is down to the headlight module, so I tried looking for it in my car but can't find it anywhere. Does is even exist on the 1986 models?

~duplicated thread, please delete~

BlackenedBird

iTrader: (5)

Just left of the brake booster on the firewall is where the single module for both sides was. The early cars had 2 modules, one for each side. Not sure if the switchover year was 86 or 87, but I know my 87 has the dual firewall mounted module.

Firechicken86

iTrader: (1)

thanks for the reply, do all models of firebirds have it?

BlackenedBird

iTrader: (5)

After they switched from the dual module as shown in my pic yes. Before they switched it was 2 individual modules that I *think* were located near the headlight itself. Radiator wall? Under the hood latching panel? Near the battery & air filter canister? Not sure, but I KNOW there were 2 individual ones before located near the headlights, just not sure where exactly.

Firechicken86

iTrader: (1)

That makes more sense, do they look the roughly the same as the newer modules?

BlackenedBird

iTrader: (5)

No clue. Never seen one. But probably much smaller since it only works for 1 headlight vs both vs both headlights. Might even be "just" relays.

Firechicken86

iTrader: (1)

Okay, thanks for the help!

TreeFiddy

My 86 did not use the module pictured, but 3 separate relays instead. One each side inner fender about a foot from the front, and one on rhs radiator support.

Firechicken86

iTrader: (1)

Do they look the same as the one pictured?

TreeFiddy

No, they're about half that size, long and square.

Do some searching, you might find a pic, or I can go take one if you like.

Here's an old thread with circuits etc:

https://www.thirdgen.org/forums/elec...headlight.html

Firechicken86

iTrader: (1)

That thread really helped! I'm having the same problem as most people where the passenger headlight goes up but won't go back down, so i'm thinking of just replacing all the relays. If you could get a picture of them at one point or another that would be great

TreeFiddy

First of all, here are the circuit and location diagrams from that thread:

TreeFiddy

Then here are the pics from my car. Note that my wiring is heavily modified, but the left and right door relays are still in the factory position.

I have replaced my burnt out isolation relay elsewhere, but I have propped the corpse up on the rad support for you, above where it used to mount.

Edit: The RH door relay is the tall one on the right end of the row of relays in the 2nd photo (they are my own additions, not factory). FYI my relocated isolation relay is the green one on the left.

Firechicken86

iTrader: (1)

You are my new favorite person

TreeFiddy

Hope you get your problem solved

TreeFiddy

Actually fwiw, my own winky headlight shenanigans were caused by a combination of intermittent grounds, and intermittent fusible links D and E. I don't know if they stick out of the loom as depicted in that diagram from factory, but mine were actually hidden inside the loom.

I didn't have the benefit of that diagram back when I was troubleshooting it, they were a beeyatch to find!

Firechicken86

iTrader: (1)

*UPDATE* So I finally found the RH relay and took it off and noticed that there's only two wires going into one of theplugs when the other has 3, here's some pictures (sorry for the terrible quality )

Notice how the one with the green and white wires are missing a wire and there's also an empty hole where it looks like the wire should go (grounding wire perhaps?)


bottom of the circuits

do you think this missing wire could be the answer to the headlight not being able to go down?

TreeFiddy

If you look at the circuit diagram a few posts up, both the left and right actuator relays have 5 wires connected, so what you are seeing with the connectors is correct.

As the rh door opens ok, the rh fusible link and ground probably ok. Problem might be the rh relay, isolation relay, or in the motor assembly itself.

Easiest thing to try first - try swapping the lh and rh relays, see if the problem swaps sides.

Ts1986TransAm

Hi. I'm new to the forum. I have an '86 Trans Am. Could use a hand if someone's been down this road. My headlights come on but they won't go up. If I manually put them up, when I turn the headlights off, they do power down (just not up). From reading the forum posts, there are 3 relays and no module for the 86 (I think). I see the 3 relays. I switched the LH relay with the RH relay, but that did nothing at all. In this thread, it is mentioned that there are in-line fuses, like down by the battery(according to the picture).. I looked there and there's nothing but wires. Any ideas? Thanks

Okay, after reading further into some threads, it seems it is most likely the isolation relay, which is located on the radiator wall near the passenger side headlight, especially since it is affecting both headlights, not just one.. BUT, there aren't any of those available to the general public. Anyone have the isolation relay they can sell me? From what I read, they are the same from 82-86 TA. Thanks