Im finally finishing up repairs on my 1989 125 force on 1990 Bayliner 1903CC and now want to start working on the gauges. All work with the exception of my fuel gauge. It illuminates, but thats about it. A friend said his doesnt work either, but hes just ignored the problem. Im a beginner when it comes to boating, so I dont want to go out and not know how much gas I have left in the tank. Where should I start looking to figure out what the problem is?