Electronics » Fiamm Horn

This has probably been posted on before but I have a Fiamm highway horn which I would like to connect to the existing horn circuit. Can you simply parallel the existing horn or do you require additional circuitry/relay to be installed. I understand Canbus limits what you can do in this regard.

Cheers,

My very first modification was to fit dual Fiamm horns. I did not like the "beep beep: of the standard horn. It invites disrespect.
I used an adapter from Nippy Normans to replace the horn connection. The 2 wires that came from the adapter were fitted with terminals for the relay. The relay runs from the battery (with a fuse near the battery). The output from the "hot" side of the relay runs to the horns, and for the first time ever (for me), the earths from the horns run back to the battery terminal. I had isolated issues with grounding to the frame on other bikes. Both Fiamm horns are hung from the bosses that would be used for the upper crash bars, and they hang down just inside the lower corner of the triangular side pieces.
I used crimp connectors rather than soldering this time. Crimped connectors are generally rubbish, the trick is not to use the "dime store" crimper, but get a good one instead. I used wiring sheaths to make up the looms and spent time tucking things away under the body work.
Hornig had a video, and may still have one, for installation.
If you want to go further, you have to do some disassembly of the fairings to get access to the original horn to remove it. My relay is mounted on the boss that was used for the horn from the factory.
If your RS has the DRL, you will have less room than if it is a US model. I could not fit my horns into that space, but others have been able to fit larger and more effective horns in the original position.

Thanks for that AI, Had a look at Nippy Normans website and found the following kit that appears to be suitable for a single horn replacement using Can-bus:

https://www.nippynormans.com/horns-and-a...-can-bus-wiring

It does not appear to require a relay etc. What do you think? I believe my horn to be a Fiamm mini blaster and that's loud enough!

I can find my way around a 20th century wiring loom. I can also read a 20th century wiring diagram. I even figured out how a 20th century voltage regulator works, but it took me almost 3 days of contemplation to understand how the "high" output points and the "low" output points actually regulated the amount of current the alternator produced. So, I don't really understand the Can Bus. For me, stepping outside the RS electronics and running a parallel circuit made me more comfortable.
The reason why high amp devices are often put onto automotive relays is due to the load. That load translates into heat. That load also means that things like switches can be stressed, degrade or suffer damage. Since I wanted my horns to have as much current as they could handle - which I believe (blind faith, I know) would give me the loudest sound, I ran 3 mm wire from the battery to the relay, from the relay to the horns and from the horns back to the battery.
The wires that go into the loom that plugs into the std. horn are much smaller in diameter. Small wire = higher resistance = heat. The horn button itself either passes the current "downstream" to the horn, or "upstream" from the horn. Either way the button will be receiving a lot more amps without a relay (my guess).
Now it may work entirely differently in the RS and the computers and what-not may treat the horn button and the horn itself differently, but I don't know the facts. If someone reputable markets a product that is designed to "plug straight in", fine. However the videos I watched in 2015 from Hornig used a relay.