This is an automatic voltage regulator that is used on many generators. Depending on the model of the generator, it can be located in the main control box, under the alternator rear cover, or in the alternator terminal box. It senses the voltage from the generator terminals and compares it to a stable reference. This is used to adjust the flow to the right level. If the automatic voltage regulator is damaged, the generator will experience a loss of voltage that causes the machine to shut down.A malfunctioning automatic voltage regulator will need to be replaced. If it isn't, the generator may not run. If it does run, it can cause serious damage to the generator. Test the main circuit breaker before testing the wiring. Next, adjust the automatic voltage regulator. If this doesn't help, check the rotor brushes. If the generator is still not working correctly, the automatic voltage regulator should be replaced. Make sure to turn it off and unplug it before doing so.This is a genuine OEM replacement part that is directly sourced from the manufacturer. The automatic voltage regulator is sold on an individual basis. The component is made for use with several generators manufactured by Generac.