In the case of an electrical wiring for a motor vehicle having a primary system which includes a voltage-controlled generator, a primary energy accumulator as well as at least one primary energy consuming device, and having a paralleled secondary system which includes a secondary energy accumulator as well as at least one secondary energy consuming device, the secondary system includes a control unit with a controllable resistor connected to the generator. The control unit monitors the charge condition of the secondary energy accumulator. As a function of the currently determined charge condition of the secondary energy accumulator, the control unit, on the one hand, controls the controllable resistor in such a manner that, during the charging of the secondary energy accumulator, the primary system is not overloaded. Furthermore, the control unit connects and disconnects the secondary energy consuming device or devices in such a manner that, during the discharging of the secondary energy accumulator, there is no falling below a predetermined residual charge value.