I was just reading up on it, and the Hot Spark web site says:
Quote:
If the charging system voltage, measured at the coil's + terminal, is more than 14.0 volts at any RPM level ... [a] ballast resistor should be wired between the coil's + terminal and the red HotSpark ignition wire. Too much voltage can damage the ignition module
Since the 1200 alternator specs are up to 15+ volts (depending on temperature) it seems the resistor is needed -- should not be optional
Internally regulated alternator is a little tighter on specs, but still goes over 14.0 volts. By the way this is for most all cars, even new cars, as they use the same lead-acid battery chemistry
There is no red X, these are the two "options":
* wire up ballast resistor in between IGN and COIL +
* no ballast resistor wired up between IGN and COIL +
For racing w/o an alternator, the "optional" no-ballast would work fine. Otherwise use the stock 1200 wiring (with ballast wired up)