Calibration

[Swedchevy67]

Need tips on how I calibrate my sending unit after put a new gas tank under bed. The fuel sender was stopped between zero and half.

[clay68c10]

The ohm range for the factory sender is 0-90. You will have to adjust your sender to get the ohm range within the correct swing of the arm to match your fuel tank.
If that sender has a different ohm range than 0-90, you may be out of luck, or will have to make some kind of resistor bridge to get it right.

[B. W.]

What Clay said. I go a step further. I measure the tank depth, make a simple diagram on paper & check the sweep with the sender out of the tank. I check it wired up to confirm the gauge is reading correctly. I also set the sender to read empty before the tank is empty.