Everything I have read indicates that the Radio Coil Resistor is not required for the car to run. It does take the voltage spikes out of the signal coming from the Ballast resistor. I removed mine while changing the intake, same as yours the wire broke so I didnt reinstall it. When I fired up the teen for cam break in it ran fine for a week, then proceeded to trash the points and condenser. So, I took the resistor and dug out around the wire nub and soldiered the wire back on then tested it with an ohm meter. It's been running great for a month now without issues. Good luck trying to find a replacement for less than a small fortune.