Hi Stuart,
I have the battery and the horn connected to the + side of the ammeter. Everything else including the alternator lead is connected to the - side of the ammeter. The wiring diagrams shows the horn (and cigarette lighter if installed) being connected to the same ammeter post as the battery. I guess they felt it wasn't necessary to measure the load of the horn when honking. The reason for my earlier question about connecting the alternator to the same connection as the the battery is because of an earlier post in this thread from Tiny suggesting that the ammeter be bypassed and the alternator connected directly to the battery. Doing a search and looking thru the history I can see that this subject has been beat to death, but the questions still remain and get asked over and over because it is still so confusing.
How is the horn relay used as a buss for the charging system, and how would it be wired?
