I have an issue with the digital fuel gauge. It is reading empty when i just filled it up. The sending unit has a black wire and a pink wire. The pink wire is in the center of the sending unit. What do i check? Can I ohm out the pink wire to ground? or how does it work. Is it strickly ground resistance readings or actual voltage on the sending unit. And if its a bad gauge can i put a regular fuel gauge on that sending unit. Thanks in advance.