I so appreciate all your input, experience and advice... Thank you!
So.... today got some good things accomplished, Not done yet. Today was prepping the truck with the help of an amazing neighbor and friend. Goal was to complete wiring with a switch for a trigger wire to the charger. Complete a wire run from rear truck running lights into the bed for camper marker lights. Run battery cables from engine to cargo bed. The three wire runs in the cargo bed will be connected to the camper. I have anderson connectors for the battery cable run to the camper. Will use weather tight smaller connectors for the trigger wire and marker lights. So a total of three connections in the cargo bed.
The wires emerge out of the forward driver side of the bed through one of the removable caps on the sidewall. The switch was the tricky part but is done and tested. It looks great and I'll post pics when done. Truck running light to camper marker light connection is raced and just needs a connection. Tomorrow we run the battery cables and terminate all the truck wires with the appropriate connector.
For the trigger wire switch, we were able to use an empty fuse slot that is hot on the driver side fuse panel. That wire exits the firewall via the hood release boot. It will race down with the battery wires to the cargo bed. The key to that is using the switch when I want the charger on or off. The switch is a simple lighted push button. So it's easy to determine if it is on or off. I like that I can manually trigger the charger on or off from the cab at will.
After the truck comes the camper. Install lithium batts, wire in charger, tap into camper marker lights, make a pigtail connection that allows all three plugs to come together in the truck bed. Once done I won't need to use the camper 7 way trailer wire at all. My camper is small enough to close the tailgate, Viola'!
So far good... just slow and methodical. I really appreciate your help, ideas and cheering me on. So thank you. More to come with pics hopefully soon. I learned so much today that i really admire the facets revealed in putting this together. Hopefully it will be a clean productive install. The joy in DIY is the fact of understanding what is going on and what to be aware of now and later.
Thanks much! Oh... and yes... the VSR is a great idea... that may be an add on after I figure this out for a bit.