Illumination device for vehicles

The lighting unit for vehicles (3) has two main headlamps (1) with dipped beam (4) and main beam (5), and a function for infrared light which is switchable separately from the headlamps on auxiliary headlamps (2) attached to the vehicle. With the auxiliary headlamps switched on these produce a visible position light in addition to the infrared light. With switching on and off of the auxiliary headlamps the position light is automatically switched on and off by a control unit depending upon the speed of the vehicle.