I'm having some issues with my gauge cluster.
When I turn on the ignition one bulb stays on, when I put my lights on that bulb goes out and the rest light up.
Next is my fuel gauge and speedo do not work.
Car has been sitting in my garage for 3 years, did an ls swap carb'd.
I did take the gauges out and clean the plug and ribbon behind the cluster with no luck. I also had another cluster, cleaned it as well with the same symptoms, so I'm ruling out the cluster.
Harness is in great shape and never been touched....I'd like to add that I am the original owner also.
Any insight you guys might have would be greatly appreciated.
Thanks
Tony

 

Something flaky like that is often a ground issue. Could try checking the headlight grounds (iirc, up front around the radiator support by the battery).

Otherwise could possibly be the headlight switch. Sitting for three years, hope it's not mice related. Or possibly something taken apart/disconnected during the swap. The flex circuit boards on the back are known to crack/de-laminate but it sounds like you ruled that out. (Hard to resist not mentioning it. lol)