I finally found a clean looking cap to fit my 2012 2500. It's an ARE Z-Series cap. This is the only manufacturer that makes this style cap for a 2011 or 2012 2500. When I had it installed, I told them not to connect the lights because I didn't want a half ass job done. I wired the cap on my 1998 1500 myself years ago. Nice thing is that they have the hot wire for the brake light ready to go sticking out of a wiring harness along the frame. My question is about the dome light for the cap. On my 98 I tied into the power distribution block but I can't find any diagrams or info on the 2012 2500 Cummins power distribution block. Can someone give me any information on this or if you have wired a light into a 2012 cummins, please let me know. I want this light to be hot all the time.
By the way, WTF, why do they give you the wire for the third brake light but not the dome light? Would it have been that much more difficult?