I ordered my new cab&chassis with the extra switch located by the air bag on and off switch it has the truck with the light on top of it I'm just wonderin where do you hook the wires or wiring harness up at? TURBO6600

I droped my headliner and poped out the 3rd brake light and ran the wire thats looped and tied up up there under the 3rd brake light. Another option is to run the wires out the little plastic vent grate thingy thats between the cab and the bed.