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Discussion Starter #21
I have this same problem. I seem to recall reading a post here a couple of years ago that a certain combination of screws holding the instrument cluster to the dash actually ground the instrument lights. If I were to guess, I think it's the two bottom screws (with their corresponding J-nuts) that are needed to complete the ground.
Thanks @BigKoppa I will check this out too. I did pull the instrument cluster a while ago when I was first trying to diagnose the problem, and believe that my grounds were secure, but I can always check again. I still have to find a moment to do the final diagnosis advice that was said earlier as well, though I am a little leery of trying to connect the two terminals since I'm not as electric savvy and don't want to short power to ground as John above mentioned. Gets me a little worried, but I just need to get in there more and see what everything is looking like. Been driving it around too much lately in this good weather to want to take it a part for a little while!
 

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I would highly suspect the headlight switch. 67GTA has given you great advice so far. The power from the headlight switch comes on wire 19 to the fuze box into Fuze 3 (2.5A). The fact that you say there is no power on this fuze points right at the head light switch. From the fuze Wire 19 goes to the instrument lights and to radio background light and Rally Pack if you have one. The headlight switch controls these lights with a Rheostat. The rheostat consists of a Tab that presses against the side of a spring. As you rotate the switch the tab moves along the spring changing the voltage to the lights causing them to dim or brighten.
Over time the spring often gets corroded and stops working. Luckily changing the switch is quite easy. Just be sure to buy a quality switch. Some of the cheap ones don’t last long.
 
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Discussion Starter #23
@Flade thanks for the info and your take on it as well! My radio background light works just fine, however, it is one that is not original and I'm confident was installed later on. So, my hope is that they did not decide to do some strange wiring to accommodate for the after market stereo at some point. I still have to get in there and examine, it's just been busy with driving right now but I know I will get into this soon and this info has been so helpful from everyone. I've not heard so many people point to the light switch as the culprit, I would be surprised if it wasn't. I almost hope that it is or else I may have something odd on my hands that will be more difficult to figure out!
 
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