2003 dodge diesel pickup, lights?

I have done this on a ford, chevy and would like to do this on a friends dogde pickup (03 diesel). Mount a set of lights under the truck so that when the dome light is on (door open or unlocked with remote) the lights under the truck come on to illuminate where you will be stepping. Anyway, I am looking for info on what wire I can use to activate the relay when the dome light comes on. I probed the wires at the dome light and if I probe to both wires in the plug I get 12 volts, but if I probe to either wire and to ground I get nothing. I even tried continuity between ground and either of the wires and no luck. Any help would be great. Claytargethntr

There is a (-) BROWN wire at the A pillar for dome light supervision. You can use this to trigger a relay to go to the lights under the truck. Use this link for the relay.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA

Thanks for the help, much apreciated claytargethntr