Today I installed some new instruments in a pillar pod. After wiring everything up I checked for proper function of all my gauges. They all worked and I finished putting my dash back together. After completely reinstalling everything I tried to turn on my dash lights and now they no longer work! I've checked for blown fuses. The one for my cluster lights was shot so I replaced it but I still don't have any cluster lights. The fuse I put in did not shoot though. I installed the lights by tapping into the dash light wire and the ground wire that are in the cluster harness. Any ideas on why they are no longer working even with a good fuse? Is there a relay or something that could have burned out?

bump. I am having the same issue. No dash lights. Many people say it can be the dimmer. I haven't replaced mine as my lights went off a few days ago too, but I was messing with wiring in the radio pod area... any help would be appreciated guys!

If it's the dimmer in my case it sure is a strange coincidence that it went out now of all times. Unless the added draw from three measly little bulbs messed it up. Hopefully someone will chime in with a more definitive guess.

honestly, I don't think its the dimmer. I wish it is because it would be an easy fix, but I too believe its a coincidence that it went out after messing with other wiring... I'm going to get a dimmer switch this weekend and I'll let you know what happens on this end...

I took mine out his morning and disassembled it. Everything on the inside looked good, no burned contacts or anything, but still no lights when I put it back in. Hopefully it will be the switch though. I won't be able to work on mine again until this weekend.

After I try another dimmer, I will look up the wiring schematics on where the dash lights get their power and grounds... BTW, do your gauges work? speedometer and tach, etc? j/w mine do. I also have aftermarket a pillar gauges with no problem

i to have no dash lights but the heater lights work ??

Yeah the speedometer and tach work. They have different power than the interior lights. The wires for the dash lights are grey (hot) and black (ground) whereas the tach (I know) and the speedo (I think) have power from a pink ad black striped wire.

I have no dash and no heater lights...

Yeah I don't have any heater lights either I'm almost certain they're on the same circuit.
HCR13 does your roof light work? Mine does just wondering whether or not yours does as well.

yeah, everything works as normal, even if I use the dimmer switch to turn on the interrior lights, it works...

Ok I knew Autozone had wiring schematics somewhere. I took me forever to find them because now you have to register with them before you can see them. These are for an 87 Firebird with 2.8.







Hopefully one of us can figure this out now that we have some diagrams.

After looking at these diagrams to me it looks like its either the dimmer switch or a burned out wire. This weekend I'll bypass the dimmer and hopefully I'll get my lights back.

You firebird guys....dont forget. The "dimmer" isnt just the little roller switch on the dash. There is a rheostat up under the dash that actually handles the dimming function.

Its a royal pain in the butt to get to...let alone unscrew and remove. When I checked mine, I just unplugged it and plugged in the new one to see if things worked.

Anyway... If you are missing all of the lights that are normally controlled by the dimmer switch, then Ide look into that. If you blow a fuse for the instruments lights, you can take out that rheostat as well.

Here is where its located...as well as what it looks like. Pics are from autozone..sorry for the size.

Part number is UDS440.





Here's where it sits.





To get to it, the best way I found was to swivel the "convenience center" down. Thats the thing with the door chime and what not in it. Then you can reach up and find it. Its fun.

Not saying this is your problem...but its worth checking into.

J.

Thanks I did not realize there was another dimmer. What purpose is the little rolling dimmer switch in the dash serving then?

Its telling the rheostat what voltage to use. I think the term for the rolling knob is the "dimmer switch"...and the other is the "remote dimmer". The "remote dimmer" is what bumps down the voltage to dim the lights. I think.... Im not an EE. hehe.

If you go into autozone, most times, and ask for the dimmer switch, that usually pops up as well.

J.

P.S.... My advice holds true only if you've checked all your new and old wiring out. Make sure none of the grey ILL wires are shorting out, as well as none of your new gauge lights. Some people will connect the pos and neg for the light, tape each connection, then run tape around both connections to neaten up the wiring. That can cause big issues if just one strand of wire decides to poke through the tape into the other connection.

And like I said...you can buy the rheostat, reach under, get the plug off, try the new part before going through the trouble of installing. If it doesnt work, just return it...and dont tell them you plugged it in. hehe.

thanks for the info Ghetto, I have a feeling thats my issue since my issue started when I removed my radio pod then re installed it...

I replaced the roller dimmer, and just like I thought, it did not resolve my issue. In the next few days (when it stops raining) I'll pull the underpanels off and look for this elusive rheostat

HC.... I can give you some tips on getting to it.

I can tell you now, you arent going to be able to just reach in and see/grab it.

I had to use a looong flat head screw driver through a little hole in the front of the dash...JUST to unlock the tab that held the plug on. haha.

Then to get to the actual piece and wiring, I had to unlatch the convienience center thing, and swing it down. After that, you can jamb your hand up in there and get ahold of it. I think I just used a small 1/4" drive ratchet to get the bolts out. There are two bolts holding the unit in place.

Like I said...when you get the new one, just try to plug it in under the dash first, before you swap them out.

Im a big dude... 6'4 and my hands are massive. So...anything under the dash is a nightmare for me. If you a bit smaller, it might be easier. Why they put something that goes bad so often in such a hard to reach spot Ill never know. haha.


Good luck!

J.

thanks for the tip Ghetto... I think I'll take all the hush panels in the area and even the radio pod. And the seat, normally that makes it easier to deal with the underdash wiring...

Well, I was able to finally get under my dash. Do I have a funny story. I spend about 30mins, taking things apart, hush panels and the radio pod and such. I decided not to remove the seat, so I squeezed myself so my back is on the floor mat and door sill digging into my back trying to guillotine my spinal chord in half. After 10mins of digging through a clusterf*ck of wires I finally located the damn rheostat. I struggle for another 15mins trying to remove the plug from the thing. What I was going to do is jump 2 of the three wires/plugs (like you would do with the ALDL to pull codes). That way I'll know if my dash lights up, just not dims and I'll have to replace the rheostat. I remove the plug, jump 2 wires. No luck, jump 2 other wires, negative. Try the last 2 sets and nothing. So I'm a bit frustrated because now I think I'm gonna have to hardwire the dash lights... I decided to check the fuses 1 more time...and guess what...the 5amp fuse is out. So I replace it and the dash lights work now...ggrrr. I wish I would have checked better earlier. But I didn't tear apart the inside for nothing. I had another wiring task to do with my tach and I took some pictures of the damn thing so future searchers can easily locate it. Like you said Ghetto, its directly above the (in)convinience center...

Haha...I told ya it was fun. You saw how nice it was to get to...now imagine if you have to remove/replace the thing. Stupid placement for sure.

I couldnt get my big hands up there for the plug...luckly there is a small opening on the front of the dash that you can sneak a long flat head screw driver through, and hit the release tab.

haha....those darn fuses will get you every time Glad you sorted it out.

87v6Bird: did you figure out your problem yet?

J.

Thanks again, honestly if I had to replace it, I don't think I would remove the old one, probably just plug in the new one and find room in there to put it...

Ok so here's my story. I dug up in under the dash much like HCR13 did until I found the dimmer/voltage regulator/I'm not really sure what to call it. My hands were too big to get at it even with the convenience center swung down so I unbolted it from under the dash so I could get at the dimmer. I removed the dimmer and bypassed it. When I hit the lights all I got was a nice puff of smoke and the smell of burning electrical components from the dimmer switch in the dash. So then I knew that the in dash switch was bad too.
I got a new in dash switch and regulator and put them in. When I hit the switch still nothing. So I decide to recheck all my wiring. When I removed the dash pad I saw the problem. A wire had gotten pinched when I reinstalled everything so it was grounding out my lights. Since I tried the switches before finding the grounded out wire I burned out the new regulator as well. But now I've got it bypassed and I have dash lights again.

Hahaha... that sounds like it was fun. Yeah you gotta always rule out grounded wires and blown fuses. I had major problems with my dash lights in my 87. The fuse kept blowing, and I had NO clue why. I traced wires, replaced switches, the works.

Finally I figured it out. You know in the firebirds, the ashtray has that spring loaded door. Well I kept change in there. Know what else is in there? The CIG lighter. A friggin dime got into the cig lighter socket. Since its close in size and hard to see in there, I never noticed it. Just kept popping fuse after fuse. Royal pain.

Glad you guys got them sorted out!

J.

Yeah, I experienced the cig lighter issue a while back... but my cig was just faulty (installed wrong from 4th gen center console). I'm glad I got that one figured out...

Ugh, you guys wanna hear a funny (but frustrating, on my part) story?
Had the dash light problem, so I ripped off the dash and tried to find the rheostat... couldnt find it. More searching on thirdgen and I found this thread (which has been most helpful, thanks guys!). Feeling pretty confidant I could locate the bugger, I just now went to look... and make an exciting discovery: There is no goddamn rheostat in my car. The mount holes are empty. And the connector is there, dangling...

...with a fuse on the end? I guess the PO removed the rheostat for whatever reason, and instead of replacing it, just slotted two wires that go to a 5amp fuse in the connector... I'm scratching my head. But I guess I know what my problem is now. Thanks for all your help, thirdgen. I'll be making a trip to autozone tomorrow.

glad you figured it out daedalous, Its happened too many times when I've gone digging under the dash with no success just to find out its a fuse...ggrrr