It makes it start, mate.
The ballast resister reduces the voltage from 12 volts to around 9 volts to protect the points from excessive pitting.
They go bad.You need a new one.
I keep a jumper wire with alligator clips on the ends in the glove box for just such emergencies. You can use it to jump across the ballast and provide voltage to the coil so that you can get to the parts store, or back home, or in my case one time, through the 17 mile long Chesapeake Bay Bridge Tunnel.
Carl
