[TBONE1964]

If you have not figured this out yet, remove the resistor from the back of the gauge and ohm it. It should be in the 85-88 ohm range across the poles.

If you get less than that, replace the resistor. I suspect you will only get around 22-25 ohms, if the resistor is bad.

This is one of the more typical reasons why a fuel gauge will only reach 1/4 full when the tank is actually full.

Typically a ground issue or lack of it will cause the gauge to peg past full (around 3 o-clock position).

Truck and Car shop in Orange CA, sells replacement resistors for factory gauges

Hope this helps,
Tom