1976 Dart - ignition switch

The black wire should be hot in ACC and run. There is a brown wire that is the ignition start circuit, a blue wire that is ignition run, a yellow wire that is the starter solenoid circuit and a red hot wire. There might be some small orange wires as well, that's for the key in light or something.
The black wire you refer to is not hot in the ACC position (rotated fully CCW).