1973 Dart No electrical power

You need to REPLACE ALL those terminal pins, and likely the ones in the mating half of the connector as well. That big wire may be heat damaged enough you may need to cut it back and splice in a new length, or unwrap the harness and replace it. I would guess that one goes to the alternator output.

If you cannot salvage the connector shell, you can either drill through for the damaged ammeter circuit and run new wire straight through, or find a connector shell. Put a want ad here in parts. There may be an outfit that repops them

The terminals are available. Mattax has a great thread on the different types of these connectors, "Packard" We used to call them "Packard 56" but that is not quite right, for all of them