We towed our 2013 for the first time two weeks ago. We have a charge wire from the coach. It powers tail lights and brake lights and turn signals.
Followed the manual. Put the air conditioner in recirculate, not that is germane. Turned off radio and headlights. Put the trans in neutral and without hitting the brake hit the start button and hit it again until it said accessory mode. Got out and locked the doors
I don't think the manual mentions turning off the headlights but we did anyway.
We use an air brake by Roadmaster.
Everything worked just fine.
In our 10 Edge "we" sometimes forgot to turn the key all the way back and it drained the battery.