Modern Vespa

The following are step by step photos of my installation of a Stebel Nautilus Compact Dual-Tone Air Horn on my Vespa LX 150. These instructions are for informational use only. If you break something, don't blame me.

Here is a gallery of the images in various sizes, in case you want to see the original huge (2.5 MB) image.
http://smorris.smugmug.com/gallery/1369843/1/64620434

I purchased the Stebel horn from California Sport Touring




Please refer to LX-150: Installing a 12V power Outlet as well as LX150: Installing a Tiny Tach For instructions on removing the Horn Cover, Legshield liner, and all wiring.


Remove the existing horn, which is under the Horn Cover, by removing the bolt that also holds the fuse block. Carefully remove the two wires connected to the horn. Pull them off by pulling on the terminal, not the wire.




Remove the original horn from the bracket, and then reattach the bracket where it was originally mounted. Use this to mount the relay that comes with the new horn. Follow the included instructions carefully. Use the two wires that were connected to the original horn as the control wires for the relay, and two new wires, described below, on the other two terminals.




One of the 12 gauge red wires that is connected to the relay goes directly to the positive terminal on the new horn. The other gets connected to the switched red wire as described in the above linked "12V Power Outlet" tutorial, as shown here.




The 12 gauge black wire is connected to the negative terminal on the new horn, with the other end getting connected to the ground wire going to the battery, also described in the above linked "12V Power Outlet" tutorial.




The photos showing the Stebel horn installed are too dark. I've included several angles, so hopefully you can tell what I've done.

I mounted the Stebel horn by using an automotive screw-type hose clamp. I wrapped the hose clamp around the bracket welded to the front of the scooter's steering tube, and then around the body of the horn's compressor. It only seems to fit one direction. I tried to adjust it so the dual horns point at the grille opening in the horn cover.










Once everything is connected, test your connections with a multi-meter if you have one. If not, turn on the ignition and press the horn button. You will now have a 139 dB horn that sounds like a semi rig! Be careful how you use it now, since it will scare the bejesus out of innocent pedestrians!

Click here to hear a WAV file of the horn. Turn your speakers WAY up, because this sucker is really loud!

Smorris requested that this Addendum be added to the tutorial.

I just bought an LX 150 and, thanks to a lot of lurking on this site, am planning to install the following safety features: Turn signal buzzer, Xenon headlight or a modulator, and a Stebel Nautilus airhorn.

I've read that some people have had their Stebel horns fail, particularly on motorcycles, but I haven't seen any failure reports on Modern Vespa.

Has anyone experienced Stebel failures?

I just finished installing the Stebel Nautilus and the twelve volt outlet following Smorris' brilliant instructions and it's a complete success, I couldn't be happier with the result.

The one thing to watch for is if you drop anything when you're working in the leg shield the odds are pretty close to 100% that whatever it is will disappear under the floorboard.

After two such clumsy moments, which required that I remove the floorboard a second time to retrieve a bolt, I shoved a couple of car washing sponges in the openings to prevent a third mishap.

Thanks for such a great series of posts.

Glad to hear I wasn't the only one who dropped a bolt or two down there. I too installed a Stebel and at the very end dropped a bolt down there. Frustrating to say the least but now I know how to take the floor board off which is good.

Nice posts... I did the EXACT same thing with my Lx150. The only thing that sucks about this install is that water gets into the compartment and goes down into the horn!!!! It kills the noise and makes it sound like a choking bird trying to cry out!!! I wish i had know this before and installed some sort of sheild device.

I installed right side up, but the photos on this topic seem to show the the horn upside down. That would make it more prone to collecting water.

Haven't yet ridden in the rain so I may yet have the same issue any way. Check out the thread on my recent one time (so far) horn failure.

I'm considering putting some kind of flap on the horn opening.

Good luck to you, and ride safe.

Anyone ever install one a PX? The room under the horn cover is a little tighter. Wondering if it's possible.

Stupid question from a newbie:

Will these instructions be the same for a gts?
Thanks, now everything seems less complicated.
Should I buy this:

http://www.amazon.com/Plug-n-Play-Wiring-Harness-Nautilus-Compact/dp/B0028ZKMM6/ref=pd_sim_auto_2

Thanks guys

M

I bought everything I needed at Radio Shack (red and white wire to run from the battery, fuse holder, automotive relay, spade connectors, etc.) and the cost was comparable, but I had leftovers for other projects.

I don't own a GTS so I can't help you there. I'm sure a GTS owner will chime in though. If you don't get a response, try starting a fresh post in the general discussion section. You'll attract more attention.

Question....

The relay and the horn, both have a ground wire. I saw in another post that the ground wire from the relay goes to the negative part of the battery..is that correct? what about the ground wire from the horn?

Thanks

Not quite.

You should run a new 12 gauge red wire directly from the battery to terminal 30 of the relay. There should be a fuse on that line near the battery.

You should run a new 12 gauge black wire directly from the negative battery terminal to the negative terminal of the Stebel horn.

The original spade connectors that were connected to the horn should be connected to terminals 85 and 86 of the relay;

A new 12 gauge red wire should run from terminal 87 of the relay to the positive terminal of the Stebel horn.

I'm pretty sure that this is the way I wired my Stebel. To be on the safe side, test the circuits with a voltmeter.

With the ignition off, the horn should not work. With the ignition on it (obviously) should work. Make sure you're not in an enclosed space when you test the horn, and don't have your ears in its path.

Hello All- I have been following a thread from Smorris' addendum posted my michael_h moderator...

LX-150: Installing a Stebel Nautilus Air Horn

I wanted to find suggestions for how to install a terminal strip that Smorris spoke of. I am about to install the Stebel horn but may want to add the 12v outlet at a later date.

Couldn't find what I was looking for at Radio Shack so source suggestions welcome.

Also, is 14 gauge heavy enough for this project or do I need to go to 12?

Looking forward to your responses!

_______________

Someone on the forum said:
Why is it called Tourist Season if you can't shoot them?!
Response:
Try some catch and release. Scares them almost as bad.

I'm almost positive I used either 14 or 16ga wire when I did the Nautilus install, and it works like a champ. It was definitely not 12ga, for sure. You'll be fine.

Hello All -
Can anyone recommend a good place to install a terminal strip for adding mods on an LX 150?

I am adding Stebel, 12V outlet, side marker lights and would like to make a harness for all and run to terminal block to keep things clean. This way I can easily add other accessories as needed.

Looking forward to your guidance.

I'm interested in this one