I’d also recommend using that Pollak 2-pin liftgate plug. It’s rated for far more amps than your DC-DC Charger will ever require, but it’s also compatible with (IIRC) up to 2 AWG wires.
For the length this circuit is going to be, If you want the charger to live up to its full potential, don’t undersize the wires. Run them the most direct route from the truck battery, through an appropriate CB and isolation solenoid, under the cab to the front of the bed, and you'll still be surprised just how long that circuit is!
This is the wire I used, and the lug crimping tool.
Here’s some pics of how I installed mine.
Starting from the front, I installed a CB and solenoid behind the driver side headlight.
From there, I ran the 2 AWG +/- 12 volt wires down to the frame rail in split loom, making sure they were in a protected path, away from heat.
Not sure if Ram is like this, but in the front of Ford pickup beds, there are a couple of plastic plugs. I used the one on the driver side to pull a wire bundle through.
I used a length of heater hose as a conduit between the cab and bed.
For the turn, brake, reverse and marker lights, I spliced into the 5th-wheel plug wires at the end of the bed, and ran those wires to the front f the bed as well.
I need a thick spacer at the front of my bed to keep the camper from running into the truck brake lights, so I mounted a plastic electrical junction box on its face to use as a spot to mount the new plugs. The plugs are both Pollak brand, round pin plugs. A 2-pin, and a 4-pin.
The 4 gauge wire goes through the camper’s umbilical cord, all the way to the DC-DC charger, which is installed close to the camper battery and connected directly to it. There are fuses on both the input and output sides of the charger.
Here’s a link to a topic I posted in Tech Issues two years ago detailing the DC-DC charger install inside the camper.
Redarc DC-DC Battery Charger:):)
