bulkhead connector

Took the 66 Barracuda out the other night, first trip out of the driveway. After a short ride to a cruise in and the car setting awhile, there was no power to the inside when I went to leave. After wiggling the wires under the dash it had power and started up, but the ammeter was almost pegged out. The next day I pulled the bulkhead connector apart to find that the terminal on the red ten gauge wire from the starter relay to the bulkhead was charred. What would cause this? The alternator is new the voltage regulator is also new. I change it over to electronic voltage regulator and it is matched up with the alternator as far as being from the same year car.