tiwing said:if you want the gauge lights to dim with the dash, attach BOTH pos and neg wires to the dimmer coloured wires (not the black ground). You can solder or use the splicers. Don't ground to the chassis anywhere for the lights and you're good to go.
tiwing said:there are 3 wires to the dimmer - ground and 2 others. attach pos to one of the others, and neg to the other of the others.
... lol makes sense to me. I've wired in 5 cars like that.