A motor provided with a secondary driving system including: a casing; a dented wheel permanently rotating during the normal operation of the motor together with the rotor inside the casing; an endless screw that can be brought into a clutch engagement position in which the screw meshes with the dented wheel and in which the rotation of the screw drives the dented wheel in a non-reversible manner and that can be removed from said position in order to allow the normal operation of the motor; a driving member for manually rotating the endless screw, the driving member rotating about the same rotation axis as the endless screw and rotating the latter by direct engagement.