Bring mountain to Mohammad not other way round.
Remember that remote alternator rectifier I mentioned months ago? You will need a dedicated 3-wire plug and socket for it to connect camper to truck.
Twist a bundle of (3) ten gauge wires and run them in a protective loom between the three (soldered) stator lead taps on the alternator. Stub wires and use anderson power pole connections. It does not matter at all which three plugs connect to which three sockets at the alternator.
Near the batteries use a THREE PHASE BRIDGE RECTIFIER off of eBay. Get a heat sink and use heat sink grease. Your voltage drop will most likely be LESS than one volt. The entire distance. I'll bet it's more like .3 volts. No I am not talking about the rectifier .7 - .9 volt drop.
The alternator will run significantly cooler, the inherent thermal voltage droop will be less, the alternator will enjoy a longer life, and yes I have done this 50+ times, with outstanding success every single time. You will end up 60+ amperes charge potential from a CS130 alternator or in your case a CS130D.