Where is the best place to get an illumination wire in an 03 silverado. i tried the wire labeled dimmer and the one labeled illumination in the wiring harness and neither seems to work. I've heard you have to get it at the switch but i cant figure out how to remove the switch. Also, what's the best place to get a reverse wire as well?

Do a search, a lot of people had the same question on that very popular truck. Anyway the ill. wire can be found at your headlight switch. Reverse wire can be found in newer harnesses or at one of the bcm plugs(very bottom of the driver side dash)