The German Lusso models do not have a battery (with the exception of the Elestart models) and use alternating current on the frame. There is a separate rectifier to control the horn (black box under the left side cover with green/black striped connection cables). This converts the alternating current explicitly only for the horn into direct current and feeds this to the horn switch. This is designed as a so-called normally open contact and closes the circuit when the horn button is pressed.
NOTE: Cannot be used with the wiring harness of the Italian models without horn rectifier.
(US)