Hello everyone! I have had problems with the lighting in my car since I bought it in August (91 bird 3.1). I spent the past 2 hours searching all different words for the instrument cluster lights and really got nothing helpful. So I figured I'd turn to a new post!

My problem:
Instrument Cluster Back Lights do NOT work. My light from underneath the mirror works, my radio light works. The lights to my Heat/AC/Fan/etc do not work. I am unsure if that is related. Also my light for the shifter plate does not work, but I don't believe I have one hooked up (missing face plate for it).

I would love to fix my cluster lights because I am struggling big time coming home from night class now. Before it never was a big problem cause I avoided night driving.

What I have done:
Checked the INST LMP fuse, along with all fuses - all good!
Replaced instrument cluster with one I knew was working
Replaced dimmer switch/light switch with one I knew was working

Now I am at a loss. Perhaps someone could point me in the right direction? I read about a wire coming from the INST LMP fuse that could be disconnected to the back of the cluster? I feel like I am pulling at straws with this now.

Thank you all!

 

You replaced all of that but did you check to make sure you were getting 12v out of the dimmer switch?

 

Also, follow this wiring diagram, check at each point to make sure you have 12v with everything on. Check the fuses and the grounds listed here too.

 

On mine, the 'remote dimmer' ($2 radio shack power transistor on a heatsink) was blown; then the po had just twisted all the wires together

Replaced cheap power transistor, all good. First, check for volts as suggested by Sick92.

 

Thanks for the diagram! I will go out shortly and test the lines then I suppose I'll look at the remote dimmer switch next. I greatly appreciate the help!!

 

Ok I tried following the diagram, but I can't find the remote dimmer. Where is it located exactly? I know it should be mounted somewhere under there because it has 2 screws holding it on. I looked all underneath the dash and I couldn't find it?

 

Here's where it lives:

https://www.thirdgen.org/forums/elec...t-working.html

Here's what it looks like:

 

Thanks for the help! I found the remote dimmer. It doesn't look burnt or anything, cleaned the contacts and still got nothing. Replaced the fuse again just to make sure. Which part of it goes bad? I read about bringing it to radio shack and replace the transistor. Would that be the circle part that has the 2 bolts holding it on?

 

Remote dimmer is no good! I tested by bypassing the dimmer and my lights came on finally! All these months of fixing the wiring and this is what was needed! Thanks for the help everyone. Now to replace the lights (3 are blown) with some LED's of a different color

 

Glad to hear you fixed it! Congratz man! =D

 

Well here I am again... I had a 'temporary' fix

I drove to school and my cluster lights were working great! Leave class and back out of parking space and everything was fine. Then I put it in drive and pop! Cluster lights went out... I replaced the fuse, still nothing. Now when I tried a different combination of pins to get the cluster lights to work, nothing happened. I had 4 unhooked and cut wires under the center console. Dangerous huh? The PO that had my car before me must have hacked away at those wires too. I electrical taped each one for a temp fix, but I have to figure where they go now. Perhaps that is what shorted the lights out?

They are 3 black wires and 1 white wire. I'll get a better look tomorrow with some light. Also an orange wire that is connected to nothing.

What do you think it could be now?

 

Pictures man pictures

 

I will, couldn't take any because it was dark.

 

You should replace the dimmer switch which is located behind the radio console area or its to the right of the wheel underneath. they sell them at Autozone or Advanced. Just search for the part and put for the year

 

I know I am right down the road from autozone so I'll head down tomorrow to get one. I need to figure first what short circuited everything because with the dimmer bypassed the lights should still come on and they don't now.

I'll post pictures this morning before I go to my morning class then devoting the day to fixing this. May run to the local junkyard to see how a few others may be wired (just got a 90 trans am in there). Thanks for all the help so far! Wouldn't have done it without the help

 

Make sure you checked the backup light fuse too. There's two fuses, you might've popped both with those shorted wires.

 

Sorry it's called "tail fuse" in the diagram.

 

I knew I forgot a fuse to check! I'll check that one too. Does it involve brake lights?

 

This are the two pictures I took once I got out of class. They are with my phone sorry for the poor quality. Best I can do. There is an orange wire attached to nothing along with those 4 wires.

I know they aren't suppose to run over the shifter, realized that after I taped them for the time being.

 

All fuses were good. I have been trying to find a wiring diagram so I know what these wires are suppose to go to. Is it possible that I burnt out the bulbs? I feel that one of those wires is to be grounded and was at one point prior to any movement?

 

Hmm. I have no idea where those wires goto except I know in my 92, theres a wire that goes to my parking brake (maybe that's one of them). And a set that goes to a box that looks like it controls the air bag...
Best thing I can say is to make sure they are taped well so they don't short again. It's highly unlikely you blew all of the bulbs. Something shorting must've caused an open circuit somewhere.

 

For reference you can see the box my 92 has that I was talking about. Maybe someone that knows a bit more about firebirds can chime in...maybe there was a light for the center console? Ash tray? AUX lighter somewhere?

 

Follow that wiring digram again, see where you have 12V again. You need to do that as a first step. Wherever you lose 12 v, you have a problem. HOWEVER, if you have 12V AFTER a light bulb (on the ground side), you have a bad ground somewhere.

 

Ok something seems fishy. When I connect the wires, all my interior lights come on... and stay on unless the white wire is disconnected. Any ideas? Tried following a wire diagram, but that did little.

 

Maybe it's a ground. If it works, connect them, electrical tape them and leave them.

 

If those wires work when connected, just connect them, and leave them like that.

 

Well when I connect them, they stay on all the time. Even with the key out all the lights stay on. I guess it's a grounding issue

 

Even with the light switch turned to off? Weird, the only way that would happen is if you are applying + voltage to the top of the circuit from that location.

Are you just connecting all of those wires together in the picture? Sounds to me like you need to do a wire trace and figure out where those wires lead to, that way you can adequately use a wiring diagram to solve this further.

There's nothing more irritating that cut up wiring from PO's, with no evidence of what exactly was supposed to be there.

Trace those wires back to the fuse box or other identifyable location. A tip for you to do this is to use an ohm meter, WITH THE CAR OFF, put one terminal on one of the unknown wires, then with the other pin put it on the metal tabs of each fuse until you get a reading or 0.0~ ohms. That'll tell you it's the same wire, then identify what fuse it is to tell you apart of what circuit that wire is.

 

Yeah with the lights would stay on even with everything off (doors shut, lights off). I feel it's a bad ground. Thank you for the pic! It will help a lot! I don't have an airbag, the guy prior to me installed a GT Steering wheel and no airbag was installed. I will have to take the dash apart I feel to follow all the wires. I've heard people talk about and aftermarket stereo being a cause, but I know mine wouldn't be the case as I made sure every wire went to where it had to. Do you know of any places to get a colored wire diagram. The ones I do have don't show the color wires I am seeing. I'm confused how I have 1 orange wire turn into 3 other wires. I have to wait till I get back home to test the voltages again and see where it's at. I'll do the ohm meter cause i'm sure that will help 10x more!

Thanks for the help man! I really appreciate it

 

It just occurred to me that when one of my wires touched the ground or metal, my ACC 20A fuse blew. (light bulb above head lights up) If I follow the diagram for the 20A ACC fuse I'll be able to find out what those wires go to and realize that when I connect them, the lights remain on and run off the ACC fuse!

Think it's a step in the right direction?

 

Just giving an update! I fixed the light problem. Bypassed the dimmer again and I had forgotten to check a fuse. (Smacks head). I did discover that those wires are taped into the ACC fuse. Followed a diagram and believe they are for the door lock switch (one part that had the orange wire) seeing as how my power locks do not work. That will be for another thread :P

Thanks again for all the help!