so i have this little problem with my 56 f100 Fuel Gauge, and it’s starting to become a burden. i Wasn’t sure what it 100% could be so i figured i would ask, and i have some ideas but i haven’t checked any of this.

The Problem: As i drive the fuel gauge rises and falls, from full to empty occasionally stopping at the actual fuel level(this is the only time i can see the real level) when I’m on the highway or in the final gear cruising at a steady RPM it seems to stay pinned on 'E' and rise slowly until 1/4 tank then go back needless to say it’s kind of erratic.

i have the factory gauges and sending unit with the original tank. do you think it is normal (i know that the 50's gauges read a little funny) and if not what could it be the sender the gauge, the ground.... and has anyone done a Dakota Digital swap into this truck with the factory tank? if so does their sender work with said tank?

 

My 53, stock set up... 6v positive ground...
My gauge wasn't working at all... (other than moving full swing on power up)....
Until I ran a separate ground wire to the sender... which I suspected when I was putting stuff back together. There is a gasket between the tank and the sender (but screws should be ok) but the tank is also pretty much insulated itself...
The additional ground wire did the trick...