I think this is why.......
Pretty sure I've found the reason for the charging wiring kluge! I had been able to see the end of a big heat sink like those on solid state battery isolators, but access was impossible 'til I removed the headlight bucket and moved the horns and all the wiring for the area. It was an isolator. buried under a pile of damp debris, with the heat sink fins stuffed with more junk. The driver's side front of the engine compartment, under the battery tray and behind the headlight cannot get much air circulation anyway, but add years of accumulated dirt, leaves and "stuff" that settled out of whatever air flow there was and there's a recipe for electrical problems. Even the cooling fins on the bottom of the isolator were full of that trash, and the nuts and crimp-on ring connectors were corroded so badly that I broke all three of the bolts off of the isolator. And that's after hours of soaking with penetrating solvent and trying to work the nuts gently back and forth. When they moved, they were broken!
This leads me to conclude that the isolator failed and a previous owner abandoned it and constructed the wiring disaster I inherited. I'm going to have to drill out the corroded mounting screws for the isolator and circuit breaker and start over with a clean working area for a new isolator. If I was going to replace the solid-state isolator with another of the same type, I would build some stand-offs to raise the isolator an inch or so and maybe drill some holes in the sheet metal in the area for better airflow. I'm going to use a relay-type isolator instead, because it's totally enclosed and doesn't need heat sinks.
Ain't progress wonderful?!?!
If it ain't broke, fix it 'til it is!