AUTO METER GAUGE WIRING HELP

I just made a dash gauge cluster for my barracuda. I got a good deal on some auto meter gauges. speedo, tach, fuel, volts, water, oil gauges. I got the all wired in except for the lights. I know the black wires are gonna go to a ground & the white wires are going to a power source. I would like to hook them up so i can dim them just like the original dash lights. Anyone have an idea where i can hook them up to ?