Blue Field Wire Meltdown?

Howdy from Texas and I am glad to join the mopar community!

I recently acquired a 1974 Plymouth Valiant. It is a great car and drove great until it developed a charging issue. I replaced the alternator and battery as they had tested bad and hooked up the connections correctly. There is no issues when key is not on the run position but when key is turned, the blue field wire melted from the alternator down to the firewall. (not quite the bulkhead connector however)

It should be noted the path to the voltage regulator is unharmed.

Where do I start from here?


Some key points, connecting a multimeter to the terminal and positive battery reads 12v as does the bulkhead connection reads 12v even when terminal is disconnected.