this is for a 79 so i am not sure if it will be 100% the same or not but i figure it has got to be similar. it has the wiring diagrams for a 79 ramcharger/trail duster
https://drive.google.com/open?id=0B7J17pYhhC6LSkxlNkFqSkJ3UWs
https://drive.google.com/open?id=0B7J17pYhhC6LSkxlNkFqSkJ3UWs