I am not sure if the attached schematic will help since it says Challenger, Miramar for 2013 (If I read it correctly). In many cases chassis wiring may stay the same over the years so its worth a try. Check out the Trailer 7 pin wiring assignments on the left side of the drawing.....says for the "charge line", black wire; ignition switched; a 30 amp in line fuse on the fire wall.......good luck with that, but it's a start. Hope it helps you out.
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