ok there will be about 4 wires and they should be labels an the back of the gauge

for mine i ran + to the + side of the coil and - to earth

as for the other 2 ,one of them will be for the park lights and the other for the rev signal , the rev signal will go to the negative side on the coil ,running the park light is optional ,but is good for hooning at night time :D ,this can just be run to the park light feed on the fuze box