Another fuel gauge mystery… 😖

[Stranny64]

My fuel gauge still doesn’t work! I found a great tech article on this site and bench tested everything with a ohm meter per that write up including the resistor. Everything tests correctly. I can test the sending unit in the truck and it is reading about a 1/4 tank which is about right according to my odometer and gas mileage tablet that I carry with. I’ve replaced the gauge with a new one, the sending unit wire, and I’ve tried two sending units. I’ve checked the truck ground straps and also ran a wire from the back of the gauge to a ground. The gauge shows full all of the time. When I disconnect the sending unit wire and touch it to ground the gauge goes to empty. Ive tried reading every article on here and I finally give up. What am I missing? Thanks!