I have seen people get stuck on this resistor issue in the past. For some reason not all wiring diagrams show the resister circuit. The deal is that when running the resister drops the voltage to the original style coil which doesn’t normally need 12 volts to run properly. This helps preserve the life of the points. In other words, this original coil probably only needs 6 volts to normally function. When you are turning the key and cranking the motor there is a separate wire from the starter solenoid which provides a full 12 volts to the coil to give it a little extra zap and helps the car start. This wire which comes from the starter solenoid goes directly to the same contact on the coil that the resister wire goes and is the one not shown on many wiring diagrams. Countless folks over the years have been scratching their heads trying to solve their starting problems because of a missing wire not shown in the diagram. I think the way its set up if the wire from the solenoid is not installed the coil does not see voltage when the key is turned to the crank position but only as the key is released. Sometimes the car will start as you release the key and the motor is still slightly turning from the starter. However it will start so much better with the wire from the solenoid.