Reply to "Suggested mods/upgrades for stock wiring harness"

Most immediate I would install a volt meter in place of the ammeter, every once in a while the ammeter gets things in the interior a little too hot (causes fires). Hall Pantera has a replacement voltmeter. Also disassemble the ignition switch and clean the contacts. That will save a lot head scratching right there.

Less immediate, electrical gremlins resulting from poor fuse connections have been an issue since the cars were new. Larry Stock, proprietor of Pantera Parts Connection, modifies the OEM fuse box to accept modern fuses. Its really not a wiring modification, just a drop-in replacement. But it saves having to wiggle fuses to get thing to work.

Eventually there are 3 loads to remove from the ignition switch: (1) The radiator fans, (2) the ignition, and (3) the headlights. The fan circuit is a wonky design to begin with, that's why I listed it first. None of these have to be done right away.

When voltage regulation becomes an issue replace the OEM mechanical voltage regulator with a solid state replacement.