Do not know what car it is off of but if there is a dash harness available for it, the connector is included. Whether you replace it or not is up to you. You can wire around the cavity that is burned up. Even though I do not know what car it came from I am betting it either was the feed to the ammeter or the feed from it. On police package alternators, this cavity was not used and the wires went through a grommet on the firewall with no connections.
Craig