Gauge cluster and HVAC doesn't light up....but warning lights do.
 

I am in the last steps of my rebuild and put my dash pieces back together...

I reinstalled the panel and gauge cluster and made sure that all plugs are firmly in.

Now when I place the key in and start the car...the warning indicators all appropriately come on and the stereo's clock lights up (like normal).

However, when I turn the lights on...the guage cluster and HVAC DO NOT light up.

Things that maybe contributing are that I did change the light bulbs in the HVAC as one was burnt out...

Also the front head light are NOT hooked up as the front is apart for the repaint...

could that be the cause or is there someplace I should look to troubleshoot the issue.

I would like to figure it out before I completely get my dash back together as it is alittle more accessible right now.

Main fuse.

Sounds like the dimmer switch might be turned down, or more than likely, you forgot to plug it in. :)

Jim...

that was what the mechanic thought also....pulled apart the dash, double checked the dimmer, unplugged, replugged...still no lights.

Clayne..will check the fuse.

You should also check the screws on the circuit "ribbon" on the back of the gauge cluster. If one of the ground screws are loose, you may not have gauge functionality or illumination.

Do you have a multimeter to test for power on the illumination circuit?

the lights for the dash/hvac are wired in with the tail lights, so see if those work.

I was having a problem cause my car kept blowing a fuse and I kept loosing my dash/hvac/tailights, so I couldnt drive at night. it was weird cause sometimes the fuse would not blow, so I know it had to be an intermittent short. I finally took apart the dash and found a slightly exposed wire coming from one of the A/C controls. a little electrical tape and no more problem.

this problem did not become evident to me until I installed my boost controller and moved around some wires back there, so maybe thats what happened to you? you moved them around and now there is a short somewhere... worth a shot to look.

Good idea.

Power flows from the battery, through the 120A main fuse, through the 60A "BTN" fuse, to the 15A "TAIL" fuse. If the "TAIL" fuse is blown, the TNS relay (tail lights, license plate, side markers) will not activate when the combination switch (headlight switch) is turned to the parking lights or headlights position.

The TNS relay controls power to the lights mentioned above, but also to all the gauge and accessory illumination. The stereo night time illumination is on the same circuit, but the display on the stereo will still be readable even if the TAIL light fuse is blown.

If your cigarette lighter surround is lighting up, or the ashtray light, for example, then the circuit is working properly and the problem is with your gauge cluster.

The gauge cluster receives power for its illumination on three different circuits. From the shop manual, terminal 1H, 2G, and 4B are the illumination circuits. All are red wires with a blue stripe, one each on three out of the four plugs that connect to the back of the gauge cluster. If you have 12V+ on all three circuits when the combination switch is turned to the parking lights or headlights position, then you can eliminate fuses and wiring as the problem, and the problem is in the gauge cluster itself.

At that point, you should check the screws on the back of the gauge cluster for tightness, since they are used by the grounding circuit. Short of that, I'm out of ideas. :)

Thanks Jim....

will try to head to to shop to trouble shoot this...

btw, the tails do work as well as the key illuminated and I think the ash tray but need to double check.

Thanks for the help...

I went to the shop today to trouble shoot the issue and instead find that my mechanic found the problem on their own time.

Since my car has been down so long (July 03) the front fuse box (one next to the airbox) must of gotten exposed to the elements and corroded some of the fuses...

he found this out after trouble shooting it from the interior first. Then popped another fuse in and poof!! Everything is alright!

Thanks for the help. I will try to take pics of the fuse and the correct name for that fuse box up front.

Just FYI, that front box is a relay box, not a fuse box. :)

The TNS relay that I mentioned above is located in that box.

Good, now you can go crusing at night with me.
I promise not to flyby a cop at 118 mph.:D

nooooo boosting until break in is done!

Thanks Jim...I'm not by the car but I do remember the relay box being labeled TNS....thanks for the tip!

I'll take a pic of the relay and gauge cluster....

After putting it all together I find that my main cluster has some lights out....so back in to disassemble the whole thing all over again!

Jim, Thanks for the detailed explination...

I bought a roller for a LS1 swap, the guy left bare wire from the ash tray light, which was grounded on a seat bolt, poping the TAIL fuse...

Your explination made a scary debugging into a 2 min job :)

:cheers:

-Jason