You did not search fuel gauge senders on FABO did you?
ALL Aftermarket senders are ****.
Here is my prediction.
You fill up the tank and it reads full.
You drive for 4 gallons worth of gas and the gauge starts to read less than full.
A couple more gallons it starts to be closer to 3/4
4 more gallons and it's at 1/4 tank on the gauge
Couple more and it's showing empty.
Assuming you have an 18 gallon tank you have used 12 of the 18 gallons
You should have 1/3 tank showing on the gauge.
But it will read empty for the next 6 gallons.
Some will say better to read E too early.
But then you end up running on E for so long and have no idea how much gas in in the tank.