Join Date: Jun 2011
Location: East Central Iowa
Sounds like you may have a bad ground connection somewhere, the clue being the weak horn. The horn is a high amp draw item, if the ground connection is weak the horn will not get enough voltage and sound like you describe.
The horn is mounted to, and I believe grounded to, the engine. Check all the mounting bolts, and follow the battery cables especially the ground cable, to their connection points and tighten all of them.
Check the wiring of the speedometer button, I believe one side of it is grounded also, which would possibly explain it and the gauges odd behavior.
For that matter, one side of the horn button is grounded also, so it's tied to all the rest of the oddities, and all of them are mounted to the moving front fork. Seems to me there's a big ground connection right up there by the handlebars, I think??
2015 RGU CVO........under continuous change......