The ET1 factory supplied Hall sensor/Hv module is very simple, reliable & trouble free ignition system IF user supplied 5.6 volt Zener & 600 volt high speed rectifier diodes are connected across both battery supply and Hall sensor wires Before any connection of batteries or ignition switch power up..These common available semiconductor devices will provide over voltage surge protection to the sensitive low voltage Hall sensor & ignition module components caused by bad grounding or high voltage leakage issues. For whatever reason, these inexpensive devices aren't factory supplied & causes lots of unnecessary ignition system failures.