All of the gauges get power from the ignition switch and as was just explained, power goes to the "I" (ignition) or "+" terminal on each gauge. They are typically daisy chained from one gauge to the next starting at the instrument closest to the ignition switch. Ground on each gauge is marked with a "-" or ground symbol and they are wired the same way -- daisy chained from one to the next. The instrument light is powered from the NAV side of the NAV/ANC switch and just like the others, are daisy chained. The fuel gauge, tachometer, and trim indicator all have separate feeds from their appropriate sender. The voltmeter if you have one does not have a sender because it is simply measuring across the +12 volt and ground lines. The fuse panel is powered from a separate pair of wires from the battery. There should be a fuse or breaker within a foot of the positive terminal of the battery.