Nevada 750 light/horn/dash electrical situation

[PeanutButter]

Hey all!

So I've run into my first "hm, I should definitely fix this" problems on my new-to-me '07 Nevada 750. The issues are all electrical, but I can't tell if they are directly related.

The first is the easy one: the right rear signal intermittently cuts out, while the right front flashes double-time. It seems to be exactly the problem described in this thread: http://wildguzzi.com/forum/index.php?topic=19326.0. It came and went on my 7 hour ride today. I didn't notice exactly when it started, but the problem stopped as I turned into my driveway. Kind of annoying, but seems like a pretty fixable quirk, unless it's combined with problem 2.

Problem 2 is a little more concerning. Whenever I honk the horn, the dashboard and indicators die. All associated lights off, no information displayed. It's not great. Thankfully the engine, and head and tail lights keep working, but losing the dash and indicators whenever I honk is highly inconvenient, to say the least. It takes about 5 seconds for everything to reset, and not everything totally rights itself. The turn signals come back on as I'd left them, and the speedo and tach reset as if I'd just turned the bike on, but the tripometer resets to zero. This is my least favorite part of these problems, as I can't accurately keep track of fuel consumption if I need to use the horn.

As far as solutions go, I eventually plan to replace the dash with an aftermarket unit; is this as good an excuse as any? I'm not too experienced with electrical troubleshooting--any and all advice is appreciated.

Thanks!

[Kiwi_Roy]

My guess is you are losing Voltage on the green wire after the ignition switch item (29), probably just needs cleaning.
Check this by measuring the Voltage at fuse     while pushing the horn button
The horn sounds a bit wimpy as well does it?

Your bike may be a bit different, this is an earlier schematic but same problem I'm sure
http://www.thisoldtractor.com/guzzi007/schematics/2004_Nevada_IE.gif

It's interesting that the horn's have a diode, my guess is to stop electrical interference back further.

I suggest you add a horn relay powered from a dedicated fuse or the 30 Amp alternator fuse. The grey wire would go to the relay coil, the other coil wire to chassis

[PeanutButter]

Thanks for the response, Roy!

The horn actually sounds full and loud, so much so that it is really embarrassing to troubleshoot this issue in the parking lot of my apartmant complex. I'll try cleaning the contacts on the green wire from the ignition switch, and adding a relay if that doesn't work out.