You don't need a resistor. Especially if you have a new gas gauge and it was designed for 12v. Actually you won't get a resistor anyway. You'd get a voltage regulator, but only if your gauge was designed for 6v...and even if it was designed for 6v if you run it on 12v it won't be long before you re-magnetize the little hourglass in there and once that happens it will re-orient and readjust itself. Until that happens about the only thing a 6v gas gauge run on 12v will do is make the needle travel faster. I think Mike got it...you have a bad connection somewhere (at the sender or gauge) or a wire is broken inside the insulation. Yes, that's rare but I've seen it happen. When you have a bad connection between your sender and the gauge, what happens is your gauge runs as far up toward F as it can go. When you ground that same wire (the one in the center of your sending unit) your gauge goes straight to E. Your gauge is looking for a resistance value between 0 and 30 ohms. Having said this, you also could have a bad sending unit. Here's how: your sending unit is a variable resistance device and it sends varying resistance to your fuel gauge by "wiping" a contact point across a resistance wiring. If your sender is bad (made badly in your case) then it is possible that wiping contact point is not touching your resistance wiring. This will produce the exact same result as removing the wire going to the center of your sending unit. I posted an image of an OEM AD sending unit which failed. I had to make a new wiping contact dot from a small screw/nut. The old one had become disconnected and hence it failed to work any longer. Which sending unit did you purchase?
Last edited by Jon G; 07/25/20239:55 PM.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
