Installing An 18" Air Horn...'Cause Bigger Is Better!

[Bedifferent]

O.k., here is the imitation.

It's after mid-night, and uncouth to test the horn now. I'll wait until my wife has an appointment outside the home.

In any case, this is one variation on the theme.

In my case, I have the SH847 R/R (recommended by @DEcosse -- tastes great, less filling) with the mount designed and fabricated by @Bedifferent. As mentioned above, his mount for the R/R, seems tailor made to provide room just so for the new horn's compressor - meeting the requirements of vertical placement and short air hose run. And all fits nicely under the left side cover (California evap controls long ago removed).

The wiring is a mess, but hey, what is hidden under the seat doesn't bother me.

In the photo below, you'll notice the relay base is there -- I'm waiting for daylight to see if there is any smoke when plugging in the relay.

In sadly typical fashion, this Chinese made item is lacking, with bad translation and nearly incomprehensible instructions. The supplied wiring is 18 ga at best, and the instructions call for 12 ga (12-24 V) and 10 ga (6 V).

I am hoping the load is significantly less than the supplied 30A fuse, as I suspect that fuse will not protect the wiring. It appears @TXtriple recognized that, and used more stout wiring in his installation. I may be following suit out of necessity. We shall see.

As for the horn mount itself, I need to follow another practice of @TXtriple and use chrome paint on the forward clamp.

In all, this installation took about two hours, with half of that just uncovering - remove windshield, remove seat, remove instrument cluster, remove bearclaw, remove left side cover, work, repeat in reverse order.

Present in the bottom photo along with the horn:

- @Mittzy coolant overflow tank

- Throttle interface unit for the McCruise

- chrome oil tank from @1K9

- Triumph chrome frame rail covers

- SH847 rectifier/regulator per @DEcosse

- Thermometer oil filler cap

Thank you everyone !

Looks good if I do say so myself. You can polish that front bracket as advised, but the rear will need a good coat of paint...your choice of color. Stainless would have been nice, but it is just to hard to work with using my primitive caveman tools. Nice job on the compressor mount....the horn looks pretty level. All is good..thanks for the picture.

 

[ken]

Fitted the 18inch air horn with a relay works perfect, my question is if I wire it with the original horn still working the horn operates when the ignition is off and I use the brake front or rear . Ignition on and all works perfect.
I am thinking of leaving it as it is to deter thieves as they will not be able to silently push the bike away. If I disconnect the original horn all works as it should. Will it cause any load problems

 

[TXtriple]

Huh....that's odd. I'd have to look at the wiring diagram to be sure, but I'm guessing it has to do with grounding through the brake light circuit. Mine works with the ignition off also, but I dont have the original horn connected. I remember that the original horn has 12V applied when the ignition is on and pushing the horn button GROUNDS it completing the circuit.

Years ago when I was working on offshore boats for a living, I "borrowed" a ground while hooking up a horn. Pushed the horn button to test it and a Detroit 8V92 came to life! Scared the bejezzus out of me.

 

[phar2slo]

Must get this done