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Anyone know if the 75 has a voltage regulator for the fuel gauge? Im getting fluctuating voltage (goes back and forth between 3 and 11.6 volts and everything in between). I have traced the wiring from the guage to the sending unit and havent found an in line regulator. Also can some one lay out the procedure for checking the guage and sending unit? Im pretty sure I got it but Ive been wrong before.

Btw the guage always reads 0. i grounded the sending unit and the gauge went almost to full. I think this means the sending unit and gauge both work?

Yup, gauge has a regulator. The varying voltage readings you are getting means the regulator is working as designed. If i remember correctly the regulator is a metal case relay looking thing that plugs into the back of the gauge circuit board.
It works like this:--- the regulator is a make and break relay that pulses voltage to the gauges. The gauges are dampened to respond slowly so they only read the average pulse voltage.
Grounding the fuel gauge sending wire should read "full" and an open connection should read "empty".
The changing resistance of the float sending unit in the tank makes the gauge read some where between full and empty.