What is the primary function of relays in automotive systems?

The primary function of relays in automotive systems is to control high-power circuits with low-power signals. Relays act as electrically operated switches that allow a low-current control signal to activate or deactivate a higher-current electrical circuit. This capability is crucial in automotive applications where the brains of the system, such as switches and sensors, often operate at low power, but need to control high-power components like fuel pumps, lights, and motors without requiring direct high-current ratings at the switch locations.

By using relays, the vehicle's design can ensure the safety and effectiveness of the electrical systems, protecting sensitive components from excessive current loads while providing the necessary control. This functionality enhances overall system reliability by isolating low voltage, low current, and potentially fragile control circuits from the high voltage, high current that operates major components.