I HAVE A INBOARD GAS TANK. THERE IS A RED AND BLACK WIRE COMING OUT
THE FLOAT . I HAVE A GAUGE IN THE DASHBOARD WITH NO WIRES ON IT.

DOES THE RED/BLACK WIRE FROM THE TANK GO TO THE GROUND/POSITIVE TO THE
GAUGE. THEN A POSITIVE WIRE GO FROM THE FUSE BOX TO THE OTHER POSITIVE
TERMINAL ON THE FUEL GAUGE ?

FUEL GAUGE HAS A GROUND AND TWO POSITIVE TERMINALS.