If the someone isn't up to rewiring all the gauges, you could just hard-wire the fuel indicator.

Another thing to look at (and I apologize if I missed this in a previous post) is how each instrument is held in. The screw that holds the instrument to the housing is also the screw that sends power and logic signals to the instrument. My first attempt at fixing my instruments was to pull them out, melt a blob of solder on the pads that the screws press against, and reassemble. FYI, the screws don't screw into the gauges, they rely on the threads to dig a bit into the copper pads. I hoped that the screw would grip a bit better and be a more reliable electrical connection but it didn't help that much.

When I hard-wired the thing, I also ran wires directly to each gauge and soldered the wires to the copper pads. This did away with not only the foil traces, but completely bypassed using the screws as electrical connectors.

If you've not had you instrument cluster out, this probably sounds a bit confusing. Somewhere I have a few photos, I'll hunt them down and post.

John
1987 XJ-S V12

 

Well, I can't find the photos I was looking for.

The fuel gauge only has three wires going to it, ground, +12 from the ignition feed, and the signal wire from the sending unit. So you could just hard wire those three wires to the gauge and see if that helps.

Thanks,

John
1987 XJ-S V12