so yeah, hooking up my new LC-1 wideband set up, and for the life of me, can't figure out the gauge wire colors.... been scouring the webs for like an hour... maybe one of you guys can help me....

here's the wire colors...

Red- 12v obviously
Black- Ground
Purple- ????? signal maybe?
Blue- ???? run to instrument cluster for gauge dimmer?

lemme know guys!!!

oh, and the gauge is a Prime Industries Wide band gauge...