A voltage regulator is a device that maintains the proper spark levels on a car's alternator. If the voltage regulator malfunctions, the alternator can overcharge the electrical system and cause many of the components to fail.
A voltage regulator allows the alternator to make enough power to run the devices on a vehicle. However, it only uses the power necessary for the devices.
When a regulator fails, the limits on how much power an alternator can produce disappear. This leaves the alternator free to produce its maximum level of power. Doing so, without using restrictions, will lead to problems such as:
- Overcharging a battery
- Damaging electrical components
- Burning out the alternator
A voltage regulator limits power by sensing the current that flows through the system. When a vehicle is turned on, the battery is set between 12.5 and 12.6 volts. During this time, the regulator allows the alternator to engage and produce power. The same process occurs when a driver turns on an accessory in the vehicle; once the regulator senses a loss in power it lifts its restraints of the alternator and allows it to produce power. When the battery reaches its maximum charge, approximately 14.2 volts, the regulator will then limit the alternator's output. This keeps the system safe and functional for the driver.