Re: adding a Tach
It should. How the sending unit works is that it is a variable resistor. the fuel gauge is like a voltmeter but graduated in E,1/4/1/2, F...instead of volts. Like Upinsmoke said about using pos from the console, I would use Pos wire from ignition with key on so the gauge works only with the key on so it's not drawing current all the time. Same with a voltmeter, connect to key on. I use a voltmeter instead ofam ammeter. when running you will show from ~13.3 - 16 volts as your battery is charging. dropping below 12 - 9 might be too much load or you're not charging. speedometers are easy. Pitot tube and light wiring.