fuel gauge problems

mopar410, you need to tell us what model and year your car is and whether you have a tachometer (Rallye dash). Early cars had a Vreg inside the fuel gage. What is this "electronic resistor" you talk of. Posting photos would help you a lot. I am guessing an electronic Vreg, but no need to guess.

Outkast. The ground for the fuel sender is the body of the sender. There should be a factory clip that connects the two metal tubes across the rubber hose. Clean it and add a ground wire w/ hose clamp if needed. After that, ground the sender wire and see if your gage goes to max. To go further (calibration), you need to measure the resistance signal of the sender and substitution resistors to check the gage.

For anyone getting a new sender, think long term. A 3/8" outlet might be better. One with a return line is needed for EFI. All exist and fairly cheap from $38 to $55. See ebay and Summit Racing.