For 1990-2009 cars

Circuit protection devices such as a maxifuse, minifuse, circuit breaker, or fusible link are utilized to protect the wiring system in case of an electrical short.

Circuit protection is defined as the application of various electrical devices in an automotive electrical system, such that the components in the system function properly during normal operating conditions, and during overload conditions. The result is the wiring assembly experiences minimum degradation.

Examples of system components include electronic modules, relays, solenoids, motors, switches, connectors, wiring, terminals, etc.

The purpose of circuit protection is to protect the wiring assembly during normal and overload conditions. An overload is defined as a short circuit to ground of a current carrying cable. The short circuit could be caused by a pinched or cut wire or an internal device short circuit, such as an electronic module failure.

The primary intent of circuit protection devices is to protect the wiring assembly, and not the electrical load at the end of the assembly. In some cases, load protection can also be accomplished at the same time.

For example, if an electronic module short circuits, the circuit protection device will assure minimum degradation to the wiring assembly, but will not necessarily prevent damage to the module.