https://tinyurl.com/yvk8mskbThat is an article I wrote about the AD fuel gauge a while ago. Your gauge probably isn't broken although if you've opened up the gauge cluster there is a chance the needle could be binding on something. If you were an electronics guy, you could go get a common 33 ohm carbon film resistor, remove the sending wire from the sending unit, turn on the ignition and connect that resistor between the sending wire and ground. Your fuel gauge should jump quickly to Full and try to go a bit further. Here is something you can check: remove both wires from your sending unit. Using your handheld meter, set the thing for resistance and measure the resistance of your new sending unit by holding one lead to ground and the other to the center post of the sender (where your signal wire will connect). Please do that and let us know. At 3/4 tank it should be somewhere in the 20 ohm range...maybe 22~23.
