A/f gauge installation on a S14

Hey guys i recently purchased n a/f gauge, but no instuctions… So i tried wiring it up the other day but i ran into a problem where when i shut my car off the gauge stayed lit up, i was wondering where everyone who has this gauge has connected, there ground, n power wire? if it helps i have three wire runnin from the gauge, one into the censor, one to a power source, and one thats grounded… i heard talk of connecting it to ur ignition switch, may sound like a noob question but where would i find those wires?

fusebox. you could just splice into the cigeratte lighter or similar

will do, ill just go into the cigarette lighter, sounds like a bit less hastle… Thanks