I have a 1975 K10 4x4. Everything works as it should. When I bought it the guy had took out the fuel guage because it did not work. So after many times running out of gas I finally decided to put it back in to see if what he told be was true. When I hooked it up the needle move to 3/4 of a tank. I thought it was working so I drove it through town to see if it would move as the gas was move around and drunk up by the built 350. Sadly it never moved. So I put a new guage in that needle didnt move at all. So is it the sending unit or have I wired incorrectly? It could be that there is more than on wire from the tank and Im not sure which is the correct one. And how many wires should come from the sending unit? Please help this important! :-(