System for power supply of the functional elements of a vehicle electrical system

The system has a power feeder (3) associated to a fuse (12), a pyrotechnic tripping device (13) and terminals to which a resistor (11) limiting power supply to operating units (1, 2) is connected. An anomaly detection unit (10) monitors current flowing in the feeder to trip the fuse. A relay and a contact are connected in parallel to a shunt and controlled by a control unit (5) to close the contact and to short-circuit the shunt.