Let's Talk 'Ballast Resistors'

What kind of voltage should one be reading at the coil I'm have a minor issue since I just reinstalled my motor with 12v on the battery and 12v at the BR I'm getting around 3v to the coil and the motor just rolls over and over with no spark. But if I let the battery charge for a couple minutes I get 13v at the BR and 5v at the coil and the motor will run very good
I'm confessed because I didn't have this problem before if the motor would roll over it would start no problem now I checked all the wiring and every thing is hooked up right with nothing damaged
I'm running pertronix ignitor with a blaster coil on a Turbocharged SLANT 6