1. An automatic control system for the lighting and extinction of the headlamps in an automotive vehicle of the type comprising at least two photo-sensitive elements, respectively connected to two control circuits to define luminosity thresholds and to produce control signals as a function of the ambient luminosity, as well as a logic control circuit having inputs receiving at least said control signals and outputs connected at least to the lower and upper beam lamps, and comprising moreover: a third photo-sensitive element connected to a third control circuit; said third control circuit defining at least one luminosity threshold and producing, as a function of the ambient luminosity, a control signal acting through the intermediary of said logic control circuit upon the side marker lights of the automotive vehicle; said logic control circuit being provided with a first, second and third inputs, to which said control signals are respectively applied as well as a first, second and a third outputs; said outputs being connected to said marker lights, lower and upper beam lamps respectively, through the intermediary of three relays; said three relays have normally open contacts and connect said side marker lights, lower and upper beam lamps respectively to the battery of the automotive vehicle; a manual control means to which the control device is connected in parallel connection, such manual control means consisting of a switch mounted in a series connection with the vehicle battery and of a three position selector, the common point of said switch with said selector being connected to the side marker lights, and the first, second and third positions of said selector being connected to the side marker lights and the lower and upper beam lamps respectively; whereby totally automatic operation is obtained when said switch is open and said selector is in its first position; manual operation is obtained when said switch is closed; and a semi-manual operation is obtained when said switch is open and said selector is in the second or third position.