Honda Hornet 600 Electrics

Hello, I have a problem with my Honda Hornet 600 from 98′. As soon as I turn on light during the ride, turn on the flasher or drop the speed too low the whole power grid collapses. Means it hardly takes on gas, Tacho plays crazy and it goes out. The alternator brings it so far in the stand fair the appropriate voltages. When I switch on the light in the stand immediately 1V goes away at voltage and does not come back. As far as the situation is concerned. someone an idea what it might be about?? My suspicion is that there is a short circuit or mass circuit that consumes so much power. A broken switch or plug would otherwise also be the guess. Is such a problem known and knows someone on which components it might be? Many greetings, Elias