Horn Fuse Rating

[1064nm]

I'm looking into changing the original (wimpy) horn to one that will be more effective in getting attention. I was planning on using the same mounting and wiring without a relay as I see the horn fuse is rated at 25A. I assume this rating also applies to the wiring and on/off button for the horn but am baffled by the note in the user's manual which describes the fuse as 25A, Load Shedding. Can anyone tell me what load shedding means and how this impacts the fuse rating.

[Jeriatric]

FWIW - Failure to use a relay can damage your horn button or circuit. The cost of replacing the horn button isn't cheap.

[1064nm]

I agree and I will probably use a relay but what does "Load Shedding" mean and does this affect the fuse rating.

[Chupaca]

You should use the relay that comes with the horn but it will work without it unless.....you like to lean on the horn. If you do not have the relay and you lean on the horn it will blow the fuse. I do not have the relay but use the horn in bursts and only when needed. I think it was mentioned here sometime back when everyone was going to the stebil and bolo badboy horns that 7 seconds and the fuese will blow but I don't know I never honk that long....

[Jeriatric]

I agree and I will probably use a relay but what does "Load Shedding" mean and does this affect the fuse rating.

I believe the main purpose is to reduce the amount of current that needs to flow through the ignition switch.

[CopperSpyder]

I agree and I will probably use a relay but what does "Load Shedding" mean and does this affect the fuse rating.

What is load shedding in Power-system protection?

or load·shed·ding. [lohd-shed-ing] noun. the deliberate shutdown of electric power in a part or parts of a power-distribution system, generally to prevent the failure of the entire system when the demand strains the capacity of the system. blow fuse or switch to relay

[1064nm]

The horn on my 2018 Spyder RT is not wired through the ignition switch.

[billybovine]

You did not say what year your RT is. But most are similar.

The 25 amp fuse is for multiple functions. Not just the horn. The circuit to the horn is always hot. So it will work with the key off. The live side of the circuit goes to the horn and it is grounded through the horn button on the handlebars. No one can tell me the current rating of that switch. So when replacing or adding another horn that draws more current I recommend adding a relay. Because if you ruin that switch it is $400 or more to replace. Many have not added a relay and say it works fine. So it's up to you. Some of the other items on that fuse are the suspension compressor and grip heaters. That part of the circuit is controlled by a load shedding relay. That relay is controlled by the ECM and only energizes the circuit when the engine is running. That way the battery will not be run down by the items on that part of the circuit.

[1064nm]

Thanks for your detailed response, it's making sense now and I will be using a relay.