Dual Ballast Resistor

Normal side of dual ballast resistor is a compensating resistance in ignition primary circuit. During low speed operation, current is maintained in this side of ballast resistor for a longer period of time. This causes resistor to heat up, and resistance to increase. This action reduces voltage in ignition primary circuit protecting coil (do not replace resistor for this heated condition).

As engine speed increases, amount of time current is maintained in this side of resistor is shortened. This causes resistor to cool off, and resistance to decrease. This action raises voltage in primary circuit which is required for high speed operation. The auxiliary side of resistor limits voltage protecting control unit.