So the wiring in my 67 was totally butchered when I got the car and I have been trying to get my fuel gauge to work for the past couple of days. I did read that there are only supposed to be two wires that go to the fuel gauge which are the sending unit wire and a wire that leads to the ignition so when you turn the car over the gauge gets power. I wired it in the other day and it didn't want to do anything so at first I thought that the wires might be in the wrong spots so I swapped them around and still nothing. Today I thought that maybe the terminals were just too rusty for the wires and the gauge to have good contact. I sanded the terminals down a bit and wired the gauge back up. When I turned the car over the power sent from turning it over shot the fuel gauge up past full. This made me think that I could have wired it wrong so I swapped the wires again and the fuel gauge dropped down to empty. I was thinking that maybe it is getting a bad ground but I don't exactly know for sure or even how to fix the ground on the gauge. Any help right now would be very appreciated. I would love to know how much gas I have so I can stop guessing on how much is left.