Frank, the correct answer from Ford is going to be different for the three trucks you show. I suspect you’re only going to get gobbledegook from the Ford CRC though. But, I’m going to give you the bottom line fix that applies to all of them.
If you’re wanting to get the best auxiliary battery charging out of your trucks, you need to install bigger cables between the truck batteries and the camper batteries. How big depends on the length of the run, but we’re probably talking 4 gauge or bigger. You also need to make the run as short as possible, which means you need to put your plug at the front of the pickup bed and NOT at the bumper.
Also, don’t use the standard RV 7-way plug for the 12 volt charging wires. The RV 7-way plug isn’t designed to connect wires that size to, and isn’t rated for the amps you want. Either use a Pollak 2-pin lift gate plug or an Anderson plug. Both are rated for something like 200 amps and 2 gauge wires.
Now, how well the bigger wires work is going to depend on the age of the truck. On the newer trucks, the charging systems have gotten “smarter” in the manufacturers never-ending quest to control emissions. I used quotes because from our point of view, they’ve gotten dumber. I can tell you from experience with a ‘95 F350, a 2010 F450, and a 2016 F450, the bang for your buck you will get from upgrading the charging wires will be less for the newer trucks.
How well the bigger wires work is also going to depend on what else is using the 12 volts in the camper while you’re driving. If all you are wanting is to maintain a charged battery, or recharge a lightly discharged one, the upgraded wires may be all you need. But, If you’re running the fridge in DC mode, or using an inverter, or needing to recharge a seriously depleted camper battery, bigger wires alone may not be enough. This will be especially true for the 2012 truck. You won’t get a FULL charge from any of them though, no matter how big the charging wires are.
Fortunately, there is a solution for all model years. A DC-DC charger will give you a smart, multi-stage battery charger for the camper batteries with sufficient amperage to more than keep up with the drain of a 12 volt appliance, such as the fridge or an inverter, or recharge the camper batteries in a reasonable length of time. The DC-DC charger still needs the bigger wires though, because it’s going to take the voltage from the truck that will be less than 14.4, and step it up to 14.4-14.6 by drawing more amps. You need the bigger wires to be able to do that.
The DC-DC chargers I’m familiar with also give you the ability to connect a solar panel to them and function as a solar controller. I’ve installed a REDARC brand charger in my camper, and I know of one other forum member who’s installed a CTEK brand. We’re both happy with how they work, but neither one is inexpensive.
:):)
