Nautilus Horn

[chief120865]

So, what would happen if one installed this without the relay? Just trying to understand the realy's role. In a rough hookup without the relay it seems to work correctly using the OEM plug in points

[John U.]

You'll burn out your horn button pretty quick.

[Grandpot]

The stock horn draws only about 3 amps and that is all the switch is rated for.  The Nautilus horn draws over 15 amps.  The relay should have contacts rated to handle this and will be connected to the horn.  The horn button will now be connected to the relay control coil which will draw only 1/10 amp.

If you don't use a relay, you WILL burn up the button.

[Udo]

And keep in mind, a relay is cheap, easy to install, and easy to replace if gone south. I don´t want to mess with the handlebar button, and don´t like burnt wires.....

[Madmike]

As further explanation of the use of relays in circuits:

A relay is an electrically controlled switch.  In simple form it has 2 separate electrical circuits.  One circuit controls the "state" of the other (the load circuit).  By activating the control circuit you open or close the load circuit.  The control circuit sees a very small electrical load as it only opens or closes the contacts of the load circuit.  The load circuit will see the current of whatever devices you install on it.

With your horn (using figures already given) the relay control load will be 0.10 Amps and the load through the relay will be 15 Amps.

A couple of things that you need to be aware of to help in selecting the correct relay for the application that you intend it for are : how much load you will be putting through it (how many amps will the circuit draw) and whether you want the load circuit to be open or closed when power is applied to the control circuit.

You can usually get "pigtails" for use when installing a relay, the pigtails allow you to hard wire the holder into the circuits and make good connections that will be weather tight and not corrode and then plug the relay in to the holder so that if it ever fails it is a simple change with no wiring involved.

If you are shopping for relays I have found them at most auto supply stores - they often have them on the open shelves around where they keep their replacement lighting products -  asking for a driving light relay and pigtail will usually find you something.  You will likely want to get an inline fuse holder and fuse at the same time to protect the wiring.

[Kingbee]

If you have a NAPA store around, just ask for a # 192 relay

[chief120865]

A relay came with the horn. Instructions/schematics are sketchy at best. Anyone have a picture or diagram that will help

[vanagon40]

Are you looking for something more detailed than this?

[chief120865]

perfect! There was nothing like this in my package. Thanks

[Rocketman]

I missed the directional instructions when I installed mine over the weekend.  I thought it was protected under my I/S pod.  Apparently not.  Rode in a gully washer yesterday, and my horn still sounds like a the proverbial strangled frog.  I'll have to turn it so the "trumpets" point downward.

[Kingbee]

I just did an install for a friend today.  I pulled the horn wires back into the neck & used them to trigger the relay. Purple wire is from battery & then to horn.



He had trans covers, so the only good place to put it was on the left side, on a bracket secured under the engine guard bolt.