QuestionI have a 69 camaro. I am trying to get the fuel gauge to work. I don't know what if any wires have been disconnected from the gauge to the wiring harness. I do know the tan wire running to the fuel sending unit is hooked up because I ran a hot wire to it and the fuel gauge on the dash moved when I put the hot wire on it. My question is, does the pink "ignition" wire and the tan "sending" wire have to have power or does just the pink wire going to the back of the fuel gauge.
AnswerYou should NEVER put power on the wire that goes back to the sender. That wire is grounded via the sender, and putting 12 volts on it will burn out the sender very quickly, and may even cause an explosion in the tank.
The wire that needs power on it is the other wire on the dash unit, and it should have power when the key is on. If it does, and the gauge doesn't read upscale, temporarily ground the wire that goes back to the sender, and briefly turn on the key. If the gauge responds by moving upscale in slow jerks until it gets up toward "full" on the gauge, the dash unit and the gauge regulator is OK, and your problem is associated with the sender in the tank. DO NOT LEAVE THAT WIRE GROUNDED for more than the time it takes to see if the dash unit responds - immediately turn OFF the key and remove the temporary ground before you turn the key on again. Failing to do that can burn out the dash unit.
If grounding the wire makes the dash unit respond as above, investigate the sender wire all the way back to the tank by grounding it to the tank metal, right at the sender connection at the tank, to see if it still makes the dash unit respond. If it does, the sender must be bad, because you have now checked out everything else.
Dick
