Re: Fuel gauge working backwards... Help
With original equipment when the float is on the top it is maximum ground. Gauge of course reads Full. As the gas levels drops the sender loses ground and moves toward Empty.
On a Chevy, when the float is on the top (full) it is at minimum ground. This is what you have now. You fill it up and that un-grounds the sender. On a Chevy gauge this would raise the needle, but you have a Ford gauge, which reads minimum ground as Empty.
See chart below were maximum ground is 0 ohm.
Ford sender: 10 ohm (gauge F), 75 ohm (gauge E)
Chevy sendr: 90 ohm (gauge F), 0 ohm (gauge E)
I think if you ground the wire that runs from the gauge to the sender you will see the needle go to F, if it is a Ford gauge.
When you're going through hell, keep going.
Putts drives a 1965 Galaxie. Rebuilt 390, 4100 on a Performer, MX, AC, PS, PB w Scarebird front discs on Cragar 17" S/S.