Ballast resistor question

The ballast is designed to reduce the voltage supplied to the ignition coil. The car starts on 12 volts (bypass the ballast resister) but continues to run on about 8 volts (voltage goes thru the ballast). The coil will not operate on 12 volts. It will burn up. Why we did this back then I don't know. They could have designed the ignition systems to function on 12 volts. I guess you make more money selling parts this way.

What year is your car? Here is a wiring diagram link you can try. You should be able to trace the wires to find their source. May help you troubleshoot the problem. Good luck, David

http://www.mymopar.com/72to76_wiring.htm