Sea to Sky wiring - does the horn circuit have a relay?

[Flier Tuck]

Hi,
Can anyone with a wiring diagram for this model tell me if the horn circuit has a relay installed, or whether I need to fit one to an air horn I intend to fit.
Thanks,
Alan.

[Big Mac]

Hi from North Wales!

I'm looking at the schematic now and I see that the horn is fed from a 25A fuse ("J5R"), but that fuse also feeds the heated grips, the heated seat and other things - so I don't know how much current is spare for the horn. Stock horns typically take about 5 Amp....I will go check....I just crawled under Joanna's new Sea-to-Sky and the horn measured 4.1 Amp.

I found your post because I too wish to fit an air horn (as I did on Joanna's 2015 RT). Which one are you fitting? I am contemplating the Denali SoundBOMB – if I can convince myself it will fit! –which takes close to 20 Amp (and thus clearly needs its own feed from the battery, as I suspect any air horn would).

[RayBJ]

The purpose of the relay in an air horn setup is to reduce the current through the horn switch & circuit. The switch can't handle the higher amperage needed to drive the horn and will burn up even if the OEM wiring is adequate so by using the OEM horn switch to activate the relay and feeding the air horn directly from the power source (battery) through the relay solves the problem.
It's a very simple $5. solution and isolates the horn from the rest of the system.

[cptjam]

Exactly right, Ray.