Hooking up digital dash in another vehicle

[hungryforinfo]

Hi all,

Have hooked up digital dash in my soarer powered car and am having problems with the fuel guage, there is a 3 wire guage (+ 2 wires for fuel pump)

Was either going to get a stock fuel sender and put that in my tank, or try and buy the right resistor and get it to work properly.

Also having some trouble with the dash telling me in Japanese that the Battery is not charging, when I know for certain that it is charging.