Messed some more with the camper.
I had a list of items I wanted to get done, more than just messing with the camper, but I ended up just getting this one item done since it had a small snowball effect before I hit my self-imposed cut off for the day.
So, I'm changing tank trays, swapping regulators and hoses, and changing the trailer plug from a 6-pin to a 7-pin. All I really need to do with the tray at this point is weld it in place, but thankfully I had the forethought to do that last as I figured throughout this process I may need to move it around or change plans altogether.
Anyway, I pulled the 6-pin plug apart. It didn't look too good inside. Yes, that wire was not connected when I opened it up, which helps explain why all of the lighting didn't work when I plugged the trailer into my truck's harness.
I'm not familiar with campers/RV's and their wiring/color coding, so I used this diagram I got online in order to know what's what (and what terminal in the 7-pin plug I wouldn't be using) and then used my truck's battery (grounded to the trailer frame) and supplied power to each wire and checked the lighting to determine if they were functioning.
Everything (the exterior lighting anyway) was functioning properly, so at that point I just made sure the wire ends were clean by clipping an inch or so off them and then screwed them in their proper location per the diagram.
When I first looked at the camper, the lady selling it had all the interior lighting going and running off the battery, so I knew things worked. A week or two later I set it up with my kids, so they could check it out and nothing was working. Great, that lady got me! I knew I shoulda had a car down the street with another 4-5 guys all packing heat when I made that deal. But not so much.
Anyway, near the battery there's an inline, cylindrical fuse that was blown. They're the typical buss fuses these older trucks have, so I had some on hand, but I figured I'd just cut out the old fuse holder and splice in a new, blade fuse holder that is weather sealed.
Long story shorter and pictureless, I had some new wire, ring terminals, etc., and went through the process of replacing all of that, heat shrinking everything, drilling out a fastener for the ground wire that broke off in the frame when I tried to unscrew it, you're typical "this'll be a 30-min job" turned into a few hours or extra stuff and running to the hardware store a few times.
I did get the regulator and hoses changed out as well, so that's good. All that's left 🤞 , again, is the welding of the tray. I'll take some pics of the rest of what I did. You can usually tell at what point someone started to get frustrated when their picture frequency declines or stops altogether when they are documenting things.