VBB 150 - Electrics - Scooterhelp When low current 12V power is put into the relay it triggers a larger switch which can handle the current straight off the battery to power the horn. See the wiring diagram for more information. The diagram at the bottom of the page changes from a standard VBB wiring to a P200E battery system with no indicators. 12volt conversion on Vespa VBC-1, lights. | All About Circuits Dec 06, 2007Your wiring diagram is not very clear to me. I found this one which may or may not be alike but which may give you an idea. It may be worth your while to deduce the exact wiring diagram of your Vespa. It takes a while but then you know exactly what you have. Related searches for vespa 12v wiring diagram 12v wiring diagramrv 12v wiring diagram12v relay wiring diagramvoltage regulator 12v wiring diagrambosch relays 12v wiring diagram12v wiring plugbasic camper 12v wiring diagram12v wiring guide