.....even just unplugging this lead was a good indication that I had found the problem the regulator side of the connector was black and charred....definitely been hot at one time......
Yep, that could be a sign of a problem.
When you swap out the regulator be sure that connection that has been hot is making a good tight connection on the new terminal. Might even be best to replace that connector if possible. After being hot they can loose their spring tension and not grab tightly. It might have loosened up over time becoming resistive which creates heat and might have caused failure of the regulator.
Many years ago I owned a 78 Jeep Wagoneer. One day in town thankfully close to home, raining, lights, defroster fan and wipers on I noticed some light smoke start sifting up from the instrument cluster.
I started turning everything off. Smoke stopped coming out. Figured ok, must be one of the switches going bad.
Stopped at a light and using the turn signal and brake smoke started coming out again.
Seemed whenever I used lights even when only w/brake and turn signal was when it started. So I slowly made my may back home using as little electric has possible. I pulled out the instrument cluster and found a black melted wire and terminal on one of the gauges. Rather then using a voltmeter the Jeep used an ammeter. One of the nuts had loosed up on the terminals. So I tightened the terminal nuts back up, wrapped some electrical tape around the melted insulation as the wire was still ok. I turned everything on that drew electric and no more smoke.