An open circuit component is closed when a turn signal is input to prevent thermal damage. A turn signal function turns OFF a turn signal resistance control when the measured current through an incandescent lamp exceeds a minimum value.

The device has sensors attached to the rear that convert waves (22) and wave reflections into visual and/or acoustic signals in a circuit by evaluating transition times to determine the distance to the ramp. The evaluation circuit (26) and the acoustic (28...