Well, that was a fun time, I took the engine harness out, plus the instrument cluster and dash harness, then did the full MAD bypass, found and repaired more than a dozen sketchy splices, cleaned all of the contacts, and applied some dielectric grease and corrected the voltage regulator wiring that was likely the reason why it was overcharging. Now the wipers, heater fan and signals all seem to be functioning properly and the alternator output is between 13.9 and 14.3 volts. Took a quick trip to the car wash across the street to flush out all of the battery acid that had leaked into the tray and frame rail area. I'm cautiously optimistic that it might yet be drivable. Next up is swapping the torque convertor, I'm hoping that when I put it together I used the motorhome convertor, and that is why it has no power down low, can't think of any other reason. Then I will need to get the horn and windshield washers working.