Hey all,
I have a 1995 XJ with 230k that's been having electrical gremlins for the past couple years. I went to replace my gauge cluster lights with LED's and that left me with nothing lit up on the dash. Every couple days the LED's will fire up, but then cut off by themselves after a couple minutes. Totally random when they come on, and it's not for long. When I remove the gauge cluster, I notice some discoloration on the plastic film thing with metal bits where the LED's plug into. (What the hell is that thing called)

Since installing the LED's my engine temp sensor doesn't move at all, it just stays far left. The discoloration is directly behind the engine temp gauge so I figure it's related. Pic below. I put in a new sending unit and still nothing. Its also worth mentioning that my voltage regulator went bad a couple months ago, and since I put in the new alternator, the electrical gauge wanders, and goes down slightly when i turn on my headlights and/or heater.

I've got no power to the radio or lights behind the thermostat, but the cigarette lighter works. There's a hissing/static noise coming from behind the radio, gets louder with the throttle. Goes away with I press the clutch. Headlights work every time. Fuses all look good except for number 9 on the inside fuse panel. I've blown the same fuse a couple times now.

When I bought this a couple years ago I had a problem with the dome, key ring, and glove compartment lights all staying on after the car was shut down. I just took out the bulbs and clipped the wires, and called it a day. Hoping that's not coming back to bite me.

I've also just put a lot of other, seemingly unrelated work into it that I'll just list here. Within the last three months: new head gasket, new intake manifold (and gasket), new valve cover gasket, New rocker arms, Jeepcables.com big 7 upgrade, New alternator, New IAC.

Thanks for reading, I know it's a lot, but I want to paint the full picture. Desperately trying to keep this thing alive despite 2020 trying its best to kill it. I've got a serious case of XJ repair video fatigue and would love if anyone had some direction for diagnostics.