74 Bronco gas guage

Greetings. I have been trying to figure out a wiring issue on my bronco's gas gauge. It will move just a little bit when I fill the tank full, but never past an 1/8 of a tank. I can flip the tank switch and the needle will go past the full mark, eventhough the tank is not full. Any feedback or ideas would greatly be appreciated. :popcorn:

try going to Jeffs Bronco Graveyard they have alot of info on the older bronks over there, it could be a bad sender or a bad wire?

I once had a 1 ton chevy truck that the gas gauge did that on, when it rained and got wet it worked turned out to be a bad connection at the sender . I fixed it by selling the truck....lol

I had a similar issue. No matter how much gas was in the tank it always read full on the gauge. Turned out the ground wire was bad on the sending unit. It had too much resistance.