Dash lighting help

[BoostedSubie]

I just finished my build on Sunday of a 93 Legacy SS that I have been putting together for the last 5 months. I bought the car as a shell with all exterior pieces but nothing else. I built it from the ground up; all wiring came from a 92 Legacy NA. On Sunday I put the battery in, started it up and it runs good. Haven't driven yet which I'm getting impatient to do since having used the Robtune, TD05/550s, FMIC, and a bunch of other goodies should be a lot more fun than what I was used to in my mostly stock turbo wagon. My problem is this: the cluster lights, temp control, side markers, and all the other dash lights won't come on. EVERYTHING else works great including tail lights, the cluster idiot lights, glove box light (which is weird as I would have thought it would be on the same circuit as the cluster). I should add since I was starting from scratch with this car, I did not use AC, auto seatbelts, airbag system, or ABS. I have done a lot of searching and I have already tried the usual stuff. I tried 3 of each: cluster, column switch, illumination module, i checked all fuses even though I put brand new fuses in for everything. I checked voltage at the illumination wires for the radio, the green wire has 12v and the yellow/blue has 10v with the headlight switch turned on. I'm sure it will either be something stupid or its a wiring issue but I just wondered if anyone had any insight. Where should I start testing? Thanks

[dscoobydoo]

Ground?
Do the headlights come on?

I think all of those are on the same circuit.
Make sure EVERYTHING in the dash area is plugged in.

[SILINC3R]

try the plugs at the fuse box under the dash. Had a similar incident and was chasing my tail and thats all it was.

[BoostedSubie]

Will try that tonight, thanks. The fuse box itself had crossed my mind as well but disregarded the thought as everything else works just fine.

[Legacy777]

Yaeh....those things are on different circuits and the only common denominator is the fuse box.

Let us know what you find out.

[BoostedSubie]

Yeah, the headlights work as well as turn signals/marker lights, tail lights, dome and map lights, brake lights, glove box light, and even the little light on driver window switch. Literally every light except the cluster, temp control, ash tray, cig lighter and all the dash switch surround lights work. Just to be sure i switched in a different under dash fuse box and it didn't change anything. I do remember seeing something about a lighting diode in the harness near the A/C cut relay above the glove box in the dash, what purpose does this serve?

[BoostedSubie]

So, I started testing the illumination wires at the switchs, the radio, temp control. Since they all use the same colors for the illumination, white/yellow and yellow/blue. Whats weird is, shouldn't one of those be ground? The white/yellow pulls up 11.5 volts (car not running) and the yellow/blue pulled up 9 volts the first time I checked it then 5.6 volts a half hour later.

[BoostedSubie]

I went and tested the wiring in my wagon to compare results and only one wire had voltage. In my wagon the white/yellow had close to 12 volts and the yellow/blue had like 300mv. I think this is the key to fixing it. Somehow the yellow/blue wire is recieving voltage than it should. I need to take a look at the service manual and figure out where the circuit begins and ends to trace down the problem.

[Legacy777]

The illumination control wiring goes to a control unit and doesn't have a separate 12v and ground wire.

[BoostedSubie]

Oh Ok. Then how do the lights get their ground? Is the other wire (yellow/blue) with the lower voltage, part of the dimming? The higher the voltage on the yellow/blue wire, the dimmer it will be? Or am I looking at this all wrong?

[Legacy777]

The dimmer provides the ground and the variable voltage to control how bright the lighting is. If any of the dimmer controlled wiring is grounding out or getting voltage separately that could be the problem.

[BoostedSubie]

Alright. I'm gonna keep checking wires.

[SILINC3R]

Again did you check the fuse panel on the driver side in the cabin. check the plugs i believe there are 5. Also there are 2 black grounds that get bolted to the tranny tunnel that maybe didn't get screwed back.

[SILINC3R]

here

[BoostedSubie]

Yes, I checked all the fuse box plugs and they were all plugged in snugly. I swapped fuse boxes also to see if that changed anything but it did not. I then switched in another Illumination control module and now the HVAC controls light up but still no dash lights, weird thing though, at first only half of the HCAC control lights lit up then after I drove the car around the block, the other half came on so it definately seems as there is loose wires somewhere. I pulled my carpet up and checked all the grounds, the two on the tranny tunnel, then there are a few under the seats. I still haven't figured it out. I should pull the dash out as you did and check all the plugs but I have been working with some other issues going on with the car lately.

[SILINC3R]

Well crap, really sorry to hear that wasn't the cause. Hopefully you get it sorted out. well if it is any help I have my dash out of the car so if you need me to look at some wires just holla

[BoostedSubie]

Alright, well thanks man, I do appreciate the help. I'm thinking there has to be a bad connector, loose or broken wire, or something along those lines.