My 68 Camaro has no wiring connected to the stock fuel gauge. Can I just connect a switched on 12 volt lead to one stud and then the wire going to the sending unit to the other stud and get an accurate reading? Is there supposed to be something else connected to the back of the fuel gauge like a resistor? I can't seem to find the original 3 wire connector up under the dash for it. And since someone else wired the car for the 94 LT1 engine, I don't want to mess around with changing any wiring, I'll run a new wire back to the sending unit if that's all I have to do.