Ignition problem
That means that one of your ignition switch circuits is not powering your coil. There are two power sources for power from the ignition switch.
One supplies power during cranking, which bypasses the ballast resistor. It is called Ignition 2, Brown wire
One supplies power in the run position, which goes through the ballast resistor. It is called Ingition 1, Dark Blue wire.
So this means your car is likely supplying power on the blue wire, but not the brown wire.
Look for broken wires near your ballast resistor as a start.
Could also be bad ignition switch.
These colors are for 1969, I think they are the same for other years.