Somebody mentioned "if it is breaker points." That is a good point
Key in "run" points open: Should be same as battery on both sides of ballast resistor and on coil plus and coil minus
Key in "run" points closed: Should be nearly same or same as battery on "key" side of ballast and coil PLUS side should be anywhere from 5 lowest to maybe 9, highest. This depends in part on the type of coil.
Coil MINUS with points closed will be a small voltage, 1/4--1 volt
Key in "start" Coil PLUS side of ballast should be "same as battery" during cranking and should be at LEAST 10V or higher