Gas Gauge

[Blue Tank]

So i tackled mine today. Break connection at tank connector and it goes to empty and to ground it reads full.
Hookup a new sender that ohms out correctly outside the tank and it will only swing from empty to 1/4 like the original sender in the tank.
I popped the brown wire from the connector where it goes into the printed board and ran leads from the gauge to the new sender on the floor. It will still only read to 1/4 so that tells me it's in the gauge or the resistor like Longhorn mentioned.
Any idea what the resistor value is? Are they available?
I'm reading about 40 ohms on the brown line back at the tank with the switch off so i think something is causing a parallel resistance which would explain the low reading of 1/4 tank?