Fuel gauge problem

Hi Guy's
i just got myself a analog fuel gauge and im having a little problem were the 2 black cables on the back of the gauge plug into so far i know

blue & black = light
white = earth
2x black = ????
yellow= ????

hopefully someone can help

cheers brad

[boats.net]

Is this a Yamaha gauge? If so then connect as
Yellow= key on power
Black= ground
Blue= backlight in gauge
White= fuel tank sender lead

Is this a Yamaha gauge? If so then connect as
Yellow= key on power
Black= ground
Blue= backlight in gauge
White= fuel tank sender lead

Thanks for the help.All working fine now

Cheers Brad