Horn power supply

[flyfifer]

Does anybody know what the horn power set up is ?
Switched 0v or 12v ??

[Paul_Smith]

I am pretty sure that all modern motor bike designs use chassis ground so all loads are switched 12v. So direct loads are Battery -> fuse -> switch -> load -> chassis. Indirect loads are battery -> fuse -> switch -> relay -> chassis and Battery -> fuse -> relay -> load -> chassis.

[flyfifer]

Triumph changed the Tiger 800 horn from a switched 12v to a switched 0v circa 2016. No idea what they have now but the 0v switching was less than handy!

I guess I will just need to check it out on the V2.

[Paul_Smith]

Originally Posted by flyfifer

Triumph changed the Tiger 800 horn from a switched 12v to a switched 0v circa 2016. No idea what they have now but the 0v switching was less than handy!

I guess I will just need to check it out on the V2.

You learn something new every day. Thanks for thee head's up.

[flyfifer]

The cynic in me says that they recognised that folks were finding the 12v ignition switched supply, to the horn, far toooo easily accessible and useful for supplying power to "aux. smart fuse/relay boxes".

So they changed it to a near useless 0v.

[flyfifer]

Which fuse covers the Horn ????

[flyfifer]

The mystery of which fuse covers the Horn remains and I have no intention of pulling them one by one to find out.
The OEM horn is mounted on a 25mm ish wide plate which in turn is bolted to a "foundation" plate. This foundation plate has two lugs which prevent the horn mounting plate rotating i.e. prevents the plate moving through vibration as it is a single bolt mounting.

I have just fitted a Denali sound bomb mini using the OEM foundation plate and a tailor made horn mounting.

The Denali needs more room than the original. The mounting plate has to move "back" 20mm or so to get the horn trumpet clear of the radiator but to maintain the benefit of the anti rotating lugs a front plate has to be mounted.
Think of the mounting as being a U shape with a short left leg and a long right leg, with a 25mm base.
The short left leg engages either lugs.

I didn't do photos of the bits sorry !

The centre boss of the horn (the coil housing presumably) is very close to the "short left leg" so the horn needs to be spaced off by 2mm or so.
The screwed stud on the Denali is just long enough.

The point is - unless you are inventive and don't mind sawing and drilling bits of 25mm wide plate as well as conjuring up spacers - don't buy  mini sound bomb.
 
An alternative is mounting the horn on crash bars or wherever with a P Clip and extend the two bits of wire.

It is louder but by a factor of what - only a dB meter would tell !!

[flyfifer]

 
I road tested the Denali Mini today and a few road users may have noticed it .
Definitely louder than stock - happy that I persevered with a fiddly mounting arrangement.