Does anybody have instructions/knowledge on testing the fuel sending unit in the gas tank? I removed the unit as it would show almost empty, but the gas tank was full. I don't know if it's the fuel sending unit or the gas gage in the dash. Any suggestions?

 

First make sure there's no corrosion build up on the sender. If there is clean it up. Put the sender back in the car and first make sure it's gounded properly. If its still not working then try this: ground the Yellow and then the Yellow/Blue wire(not at the same time). If the needles deflects when you do this then the sender is bad. If the needle does not deflect then it's the gauge OR the wiring between the gauge and the sender. If you've got an ohmmeter then check for continuity between the ends of the sending unit wires to ensure there is no open circuit.