From a DIY thread posted by Dutchpilot on the DP, I bought some new GM/Chevy led cab lights for my truck. I made my own wiring harness, which was just 18 gauge red & black wire, heat shrink, solder, and female pins to fit the factory lights. I wired them up with a simple on/off switch, which was connected to the overhead light's 12V source. Dropped the front half of the headliner down for access and the rest went smoothly.