Which is bad, Fuel gauge or resistor?

[leftybass209]

I thought my fuel gauge was functioning properly as I had about a quarter tank, and it read a quarter tank. After I filled it past 3/4 I noticed the fuel gauge still read 1/4 tank.

I verified the sender is correct, reading 1.5 ohms empty, and about 92 ohms full.

When I operate the sender by hand, the fuel gauge will go to empty with the float, but will only stop at 1/4 tank when the sender reaches roughly 20-23 ohms.

Wiring and grounds are all great!

I have the fault isolated to the gauge, or the resistor on the back of the gauge, but I'm uncertain how to check which it could be.

The gauge will read empty when the terminal is grounded, but only reads to about 1:30- 2 o'clock position with the wire unattached.

Any ideas where to go from here?