Which wire???
 

I have an '06 Dodge Diesel Dually with the factory hitch and wiring. I want to install a back-up alarm. Which wire or color is the wire feeding the back-up lites in the harness? I want to splice into it. I don't want to punch holes with my tester trying to find it. I know I can come off the plug but I don't want to do that. Thanks, Michael

if ya can see wires it think it's gonna be the purple wire

here's a link from another thread

Trailer Wiring Diagrams

Just open the door while backing up, it will give you a nice back up alarm...lol

Clicky here and you can see exactly which wires you will want to use!! Dodgetrucks.com Body Builder

I recommend downloading them because as they put up newer trucks, the older ones go away.......:w2:
HTH,
Dan