Well, back at it.
Looking at the wiring for the hot water heater, I was going to need a 12v power supply. The camper didnt really have an excess of available 12v, and I have a lot of future plans..
I found there was 1 12v plug in the camper, that for some reason had 10 gauge wire strait to the battery with no fuse. Pulled those, fused the hot, and while I was at it re-ran both those and the camper's 12v feed so that hot came through one hole in the battery box and ground in another - if they ever chafe, they won't short. I do need to add some grommets here, but didnt have them handy, so later..
After digging around in the camper for a while, I found some good usable space behind the dresser drawers. Mounted up a 6 port ATC fuse panel fed direct from the battery.
My switches for the water heater havent arrived yet, but since I'm this far along I had some other 12v I wanted to add. To start with, 2 dual port power centers, each offering a 12v lighter outlet and 2 USB ports.
One over the counter:
Another by the step up to the bed.
