Alternator Troubles! 1973 Plymouth duster 318

OP first thing you do if you have not is wander over to MyMopar.com and download the factory service manual, free, and also the third party wiring diagrams. Those are zipped, and you have to extract them and pick the correct one

If you look at the diagram already posted, the key switch "run" line, IGN1, comes out into the engine bay, and branches off and feeds the ignition, the alternator field, the VR IGN terminal, electric choke if used

DID YOU MODIFY the ignition system, ballast resistor, or is the wiring in that area up near the bulkhead connector and ballast resistor ----is that modified or damaged?