Short under the dash.

sounds like the ignition switch or direct switch wiring is shorted somewhere if you get smoke in OFF. start from the connector in hand, pull all fuses, disconnect battery, check for shorts to ground. disconnect everything you can reach, relays, regulator, ballast resistor, coil, firewall connectors, bulbs, etc...etc... get a meter and a wiring diagram from mymopar site. I just re-wired 2 barracudas and found multiple bad wires and connections in both with a meter. One major meltdown was the horn circuit, very odd. the other was the charging/starting circuits. (probably your problem)