[dscott]

RZ, The amp gauge is an in-line. Positive on both sides to show current draw. It needs to be in-line with the other gauges. If you ground it the fuse will pop. A voltmeter will have a ground and a hot.

There is no way to check the ohms on the sender unless you can move the float so, it must be pulled. I would call whoever sold you the tank and the gauge to see if it's a match. If it is then you must have a wiring problem, pinched or broken? Or no ground to the frame.

On the solenoid the extra wires with the battery cable are the charging circuit, and power to the circuit breaker, # 109 is from the regulator. You don't need any other wires. Make sure the extra wires are not on the starter side.

Don