Circuit Breakers (Thermal Relays) — General Information (BMW 3 Series E46)

Thermal relays are used to protect components such as electric window openers, door locks, and headlight adjustments. Some circuit breakers are located in the fuse box. On some models, thermal relays are reset automatically, i.e. when an overload occurs in the circuit, the thermal relay opens immediately, then, after cooling, returns to its original state. If the circuit does not return to its working position, it should be checked immediately. Normal operation of the thermal relay confirms that the circuit is in good working order. Some circuit breakers are equipped with buttons for manual forced return to the original state.

(The article text was copied from an online resource: «bmwman»)