110 fuel gauge

Hey up my friends,fuel gauge stopped working months ago so replaced with a second hand gauge and a new tank sender unit,I get power to gauge and power to sender but still nothing,would that mean a earth fault somewhere,there are only two wires to the sender one is earth and one is to the gauge but there are three terminals on sender,I have tried all combinations but still nothing,any ideas,thanks. 1990 v8 110

Ignition on, if you touch the lead at the sender unit that has power on it to a good earth does the needle move to full? if so it means that the fault is either miss connection at the sender, the sender earth wire is open circuit (can check it with a meter) or the sender itself is duff or stuck in the empty position. If the needle doesn't move and you have voltage on the wire then it looks like the gauge if faulty.