I had the same issue with my KZ650-C1. The stock horn worked but wasn’t very loud. I wanted to preserve the stock appearance. So here’s what I did. I left the stock horn in place but added wiring to the stock horn wiring such that it now operated a relay in addition to the stock horn. I use that relay to operate a Fiamm horn which is tucked in behind the steering neck. That additional horn cannot be seen, but is certainly can be heard along with the stock horn. I used a FIAMM 72112 Freeway Blaster Horn (Low Tone - F) horn (see
) and a JEGS Performance Products #555-10556 relay (see
Here is the wiring diagram for my additional horn:
Here is what it sounds like (click on FiammHorn_2017-07-07-2.mov below):
Yes, you are on the right way.
A relay can connect higher ampere without burning or melting together the switch button or over heating the cables
In the horn circuit you have to use cables with a thicker (cross-sectional area) copper core to get the best current flow.
A little detailed over view of the electric circuit
Ed, Is there a horn that can be mounted in the stock location and fit within the front frame tubes toward the top behind the frame brace ? I haven't removed the stock horn but appears to be about 4" across. The stock horn is 12V 2.5 amps 105 db., so would one horn with a larger db rating be a noticeable difference in noise output ?
650ed wrote: . . . Fiamm . . . If you use it in place of the stock horn I would still put it on a separate relay to ensure there was no overloading of the wiring or horn button switch. Ed
As known, a relay enables using a larger-than-stock wire to provide voltage from the battery positive terminal to the horn, and sometimes may also be used to provide a heavier-than-stock ground wire from the horn to the horn button.
In more youthful days, I used dual Fiamm horns on a 1973 Z1 for several years as replacement for the stock horn without noticing any wire-overheating issue and without blowing the 20 amp fuse. I used the Fiamms in typical horn manner for producing relatively short blasts. At the time it simply didn't occur to me any need to test for stock wiring and/or fuse limitations, or by keeping the horn continuously blowing for a prolonged period.
The Fiamms were the closest to a semi truck horn that I could find at the time, and the loudest available without using the more ear-piercing air-horn style. And this may still be true today.
According to various reviews on Amazon, owners are still installing Fiamms without a relay, while using the stock wiring, and without blowing fuses.
All that said, using a relay does seem to be the safer and better practice when installing the higher amperage Fiamm horn(s). However, lack of a relay with Fiamms should not necessarily result in fuse-blowing or over-heated stock wiring when the horn button is pressed in typical short-blast horn-blowing fashion (not for prolonged continuous horn blasting -- who does that anyhow??).
I don't know what the high note sounds like alone, but the low note is pretty loud. This YouTube video: shows a test and it sounds very much like the test I ran after installing one low note horn on my bike which sounds along with the stock horn (click on FiammHorn_2017-07-07-2.mov below ). Keep in mind that sound is measured in decibels which is a measure of a pressure wave, so unlike some things one cannot simply add up the number of decibels from multiple sound sources to determine how loud something is. As an example, if there are 20 telephones ringing in a room the total sound certainly is not 20 times as loud as 1 telephone ringing in a room. If it was call center workers would quickly be deafened. Consequently, using 2 horns does not make the sound twice as loud. Instead, it may change the pitch of the sound heard even though the sound level is approximately the same. Ed
Received my "Low Note" Fiamm 72112 Horn today . Pretty Anemic was expecting more. No comparison to the stock KZ Horn I have on the bike in noise level and sharpness. Stock horn is rated at 105 db @ 2.5 Amps.
Maybe just keep what I have or look for something else, but if this is what aftermarket horns sound like other than an air horn, then the search is over.