Had a couple more hours to spare this weekend and decided to fully remove the lower dash to access the entire harness as I said I was going to.
I couldn't get the steering wheel off even with a puller (the jaws were too short to grab the metal and were just grabbing the rubber).
I cut a small part of the lower dash away to allow it to go over the steering column, and the cut out part isn't visible when reassembled with the upper dash panel.
I was able to clear away the big 'ol mouse nest (I knew had been there) and check for signs of chewing. None.
For some reason they put the fuse panel on the bottom right but ran the whole rear lighting harness along the left. Shook my head at that, but anyway.....
I checked for continuity from the right rear lights that "were" working. Good up to the fuse box, colors of wires change randomly, then on up to the switches.
Everything looked good. Showed continuity from back to the switch.
Used a test light and could see power to the switch, and as I operated the switch I had power to different wires, but still had no rear lights.
Checking along the harness there were no rubs or anything. Once I got to the connectors that come from the engine compartment through the cab I noticed things
flickering again as handled them.
Humid as hell today and two hours in my own soak I decided to use a small stabby tool and tweaked every blade connector I could and said that's enough. It's going
back together.
Routed harnesses, reassembled one of those and three of those and got the dash back together.
For a sense of closure I started 'er up and turned everything on.
Even the horn worked !!! Never did as long as I've known this machine (about 10 years). !!
Had low beam headlights but no high beam. That could easily be bulbs burned out. The previous owner fixed nothing on this thing as I said before.
Only thing not working is the left rear marker light, and that is the worst socket of the bunch for rust on the inside. I suspect a new socket will solve that.
I'm going to replace all the relays. One had a little green sweat at the terminal side of the casing but nothing inside. And during reassembly I put the original 3 pin flasher
back in which made a steady buzzing noise when 4ways were on, so I put the replacement 2 pin back in and 4 ways and signals worked fine.
Looks like my adventure may have ended.
Until the first time I move this thing, hit a bump, and it all goes out again
Final result, lots of loose connections. No other corrosion than mentioned before. And years of neglecting things which means I had no idea where I was starting from.
Could have been one connector causing it all, could have been more than one, could still be some burned out bulbs. Who knows.