Systems and methods for modulating power provided to a heating element of a vehicle exhaust system is provided. One system includes a controller controlling a switch, and an alternator having a first field terminal input, wherein the first field terminal input is connected to the switch. The system further includes a heating element connected to at least an output of the alternator. The controller is configured to determine a power demand for the electric heating element and modulate the first field terminal input to cause the alternator to provide power to the heating element according to the power demand.