fuel gauge problem

[Vegas69]

I'd verify your sender is good. You can measure the resistance at the tank when it's close to empty. You should see very low ohms. Say 10-25. Regardless of the gauge you shouldn't see the gauge go towards full as your tank emptys.

[ErikLS2]

Todd is right and great pictures. I think you have a Ford gauge though. Ford senders read higher resitance when empty and lower resistance when full, GM is just the opposite 0 ohms at full and 90 ohms empty.

So, if you have a fuel level gauge for a Ford used on a GM then as the resistance of the fuel sender decreases as you use fuel, the gauge meant for a Ford will go towards full. If you can't find out if the gauge you bought is for a Ford, remove the wire that comes from the gauge at the fuel sender and ground it (through a 10 ohm resistor if you have one), if the gauge pegs at full, it's the wrong gauge.

[Vegas69]

Todd is right and great pictures. I think you have a Ford gauge though. Ford senders read higher resitance when empty and lower resistance when full, GM is just the opposite 0 ohms at full and 90 ohms empty.

So, if you have a fuel level gauge for a Ford used on a GM then as the resistance of the fuel sender decreases as you use fuel, the gauge meant for a Ford will go towards full. If you can't find out if the gauge you bought is for a Ford, remove the wire that comes from the gauge at the fuel sender and ground it (through a 10 ohm resistor if you have one), if the gauge pegs at full, it's the wrong gauge.

Great call