The Honda PCX / Forza / ADV150 / SH Forums

The Stebel Nautilus is a good upgrade for the stock horn. Here's a quick summary of installation. This is not a how-to, it's not quite descriptive enough.

EDIT: more beer was consumed during this writeup, so if you don't like cussing, fuck you and go somewhere else.

Start with:

Stebel Nautilus, Stebel Nautilus wiring kit, beer (mandatory).

You'll need a ratchet set and a philips-head screwdriver as well. To crimp the connectors, you will also need some needlenose pliers.

Disassemble your scooter. Take off the seat, rear wing, fuel cover panel, tail assembly (including side panels) and you'll get this:


You'll also want to loosen the lower-left floorboard, and the main left front fairing from the front inner fairing. Go ahead and remove your horn while you're at it. It's at the front-right of the bike, just in front of the fuel cap. Unplug the two wires to it, then use your ratchet to remove it.

Once your stock horn is out, you'll want to wire up your Stebel Nautilus to test before "installation." I put it in quotes, because space is so tight that you don't really install or mount it -- you really just jam it between two fairings -- but more on that later...

The wiring instructions are in the wiring kit, but it is quite simple. assuming you replace your stock horn. The Stebel Nautilus draws about 30A, which is 3 times more than the stock horn, hence a bit of an installation. In order to trigger the horn to activate, the Nautilus comes with a relay. A relay is, at its simplest, a powered switch that allows a low-amperage circuit (the 10 amp stock horn circuit) to trigger a high-amperage circuit (the 30 amp Nautilus). You press the horn button, the horn button triggers the relay, the relay triggers the Nautilus. Easy enough.

The relay has four connectors. One is for the battery input, one is for the horn +, one is for signal +, and the last is for signal ground. The instructions are very clear on which wire goes to which numbered input on the relay. Start by hooking up the relay to the signal + and signal ground, which are the two wires that go to the stock horn. I just put my relay right where the stock horn was and plugged the two wires in.

Next, I made a cable using the red wire from the wiring kit and the included fuse to make a positive wire for the battery input on the relay. I used the needlenose pliers I had to crimp a connector that hooked up to the relay to one end of the fuse (which end does not matter with fuses), then crimped a wire splicer to the end of the other end of the fuse, splicing the fuse to the red wire. I then crimped on a ring connector to fit on the terminal of the battery, and ran that end of the wire to the battery box (note: do not hook this up to battery yet). Plug in the end that the fuse is attached to, to the battery input on the relay.

Next, I crimped two connectors to either end of a short white wire. That wire hooked from the horn + to the horn's positive input.

Finally, I crimped a connector to one end of a black wire, and a ring connector for the negative terminal of the battery on the other. I plugged the connector end into the negative input on the horn, and connected the ring connector to the negative terminal of the battery.

Last, I connected the positive input to the relay to the positive terminal of the battery.

I apologize for not getting pictures of my wiring harnesses. This stuff is self-explanatory to me, I have a background in electrical engineering before I switched to software, and just didn't think of taking pictures... Regardless, this is what the horn and relay looked like after being hooked up. The horn isn't mounted yet, it's just chilling out on top of the fuel cap:


Go out of your garage and honk your horn. If you hear the loudest fucking horn you've ever heard, congrats! If your brake lights don't work anymore and you heard nothing, you wired it wrong. Look at my instructions again, look at the wiring diagram again, replace your 10A horn fuse in the fusebox, and try again. If you were an idiot and didn't leave your garage before testing the horn, enjoy being deaf, you idiot.

I think this is a good time to note that, in the instructions, it includes instructions for a positive-triggered horn and a negative-triggered horn. Relays are awesome, because they don't give a fuck about that shit. Look closely, and both wiring diagrams are the same. Don't get confused by this, just take it slow, keep in mind what I said above, and you'll be cool. Worse-case scenario, you'll wire it wrong and blow a fuse, make the horn be on continously, short your battery (you'll see a huge spark if you do that sort of idiocy), or nothing will happen. :mrgreen:

Now that your hellraisingly loud horn is blaring at max capacity, cram that motherfucker gently into here:


You'll have to GENTLY bend the fairings to wedge it in there, but it'll fit. In case you're a fool and can't see where the horn is, this'll help (note that the forum isn't wide enough to fully display the image, so right-click and click view image for maximal viewage):


And here's what it looks like from underneath, looking up behind the front wheel:


You can barely see it to the right of the forks, just the top peeks out.


Enjoy your ghetto blaster, and use earplugs if you feel like honking in the garage.

Hahahahaha! I want a YouTube to hear this little monster!

Ok, I know i need a new horn... I was browsing Harbor Freight's website and came across this horn http://www.harborfreight.com/automotive ... 94117.html. To me, it looks pretty similar, except has some stickers on it. it is a little quieter as well at 118dB vs 139dB. I always have a 20% off coupon and could get it for $30. I'm all about saving money and saving $30 compared to the name brand is always something I'm up for.

Anyone else think this thing looks pretty decent? Or should I just stick with the brand we knows works and fits?

That's a tough call... The one you linked to is also on Amazon, here: http://www.amazon.com/Wolo-Model-419-Bl ... 463&sr=8-6. It seems to have gotten good reviews.

I tried using this horn: http://www.harborfreight.com/automotive ... 40134.html from Harbor Freight before I bought the Nautilus. The horn and compressor were usable quality, but the relay MELTED the first time I used it. They wouldn't return it either, they claimed it happens all the time when people wire the horns wrong... Only problem is, I didn't wire the horn wrong. I followed the instructions exactly. Gah.

Since it is mentioned that the Horn need a lot of batterie Power,- hows Batterie Life time affected? and,- when honking at Night,- does the Light go out?

I can't imagine battery life would be affected unless you held down the horn for several minutes.

The light stays on when honking, and does not dim at all.

The horn draws more amperage than the stock horn, which shares a circuit with other components, which is why it requires its own relay and power line.

Check this out…

I go on YouTube to see what a Sebel horn sounds like. Is it something I want? Here is the third video I found:

http://www.youtube.com/watch?v=oVKM8jSwBU0

Can’t believe the guy standing at the garage door looks (and cusses) just like my amazing scooter mechanic! Shur enuff, it’s Bobby Carver! Best scooter mechanic in the region. I would drive to the next county to have him care for my bikes! After learning his reputation, I went on a hunt to find him, and to my amazing good fortune, found his shop is a block from my house!

maddiedog wrote:I can't imagine battery life would be affected unless you held down the horn for several minutes.

The light stays on when honking, and does not dim at all.

The horn draws more amperage than the stock horn, which shares a circuit with other components, which is why it requires its own relay and power line.

I noticed in Italy the horn seems to be the primary control instead of indicators so maybe there could be a battery issue for anyone brave enough to ride a PCX in vespaland.

I just ordered my Horn from Bengt.
There is a fine wiring Diagram on his webside, but i would like to add a Switch to be able to switch from the Standard Horn to the Airhorn.
Since I am an electrical Idiot could someone alter this Diagram in a Way that i can see where to set the Switch???
All help is greatly appreciated.
best regards from Phuket/Thailand

McGee - Do you want to be able to do one or both?

If you get a DPDT switch, you can just keep both wired in and put the relay signal for the airhorn on the one set of poles, and the stock horn on the other set of poles. With the switch in position 0, it will complete the circuit to trigger the relay if the horn button is pressed, and with the switch in position 1 it will complete the circuit to power the stock horn. Does that make sense, or do you need more clarification?

Got my Horn today, thought that i could spend some valuable Time to install it and enjoy the Music. But it came without wiring Kit, and here in the wilderness of Thailand you need to search for Days to get a Switch, good Cable,- not to mention a flying Fusebox. Sheeeet.

I figured I should add an update, since I referenced this from another thread. First off, you can probably snake the wires to the battery box and just take off the fuel flap cover and seat. That should save a LOT of time.

Also, I moved my horn to the front, underneath the meter cover. It is way louder there:

If anyone in Atlanta wants an aftermarket horn installed, go buy one and PM me. I'll install it for a 6-pack of beer, as long as you don't mind bringing it to my garage so that I can get better pictures for this how-to, the current ones are fairly awful.

Great write-up! Though I have to say, man that's a lot of work. I've wired a few pairs of Hella horns for cars that were less complex. Thankfully the horn for my bike was just two bolts and that's it, looks like if I upgrade the wife's PCX I'll be busy for a while. We shall see. Good to have a walkthrough, always.

Note to anybody else trying this - I have a 2013 PCX 150 and the insides of my scooter look a little bit different.

I ended up putting the horn inside the front fairing, above the headlight, but even there it was a tight squeeze.

^^^ Welcome to the Party! and thanks for the input. Would you mind sharing with us the make horn you installed on your 2013? Did you happen to take any photos of your horn placement? If so, could others see a few?

I have a 2015 and I've been contemplating on installing (or having someone install) a Screaming Banshee horn http://screaming-banshee.com/all-products. I'm just not sure if I need that kind of Blast power. But then, with this Banshee horn you can activate either horn at will. The stock, toot-toot or the blast (even with flashing lights - see website). Got the horn already. Got to make mind up. Too many decisions to make these days

I installed a Bad Boy Horn on my 2013. It wouldn't fit where Dave said the larger after market horns should fit. I ended up stuffing it in the very front opening and pushing it down into that area far enough to put the black cover over it. Dave and I worked on it for quite awhile. I then used tie wraps to make sure it wouldn't slip while riding. I tapped into the horn wires to connect the relay. I ran the inline fuse along the frame and tie wrapped the wires. Since I have multiple things going to the battery, I had to come up with a way to connect so many wires to a single battery contact. Three is its maximum. I tried four and they wouldn't stay connected. So I merged two of the wires together into one larger one (two 18s into a single 16 gauge). I did the same with the ground wires. I wanted to hook up a junction box of some sort, but I have to determine where the safest place is to put it. Meanwhile, merging the wires is the best solution I can think of.

Mel46 wrote:I installed a Bad Boy Horn on my 2013. It wouldn't fit where Dave said the larger after market horns should fit. I ended up stuffing it in the very front opening and pushing it down into that area far enough to put the black cover over it. Dave and I worked on it for quite awhile. I then used tie wraps to make sure it wouldn't slip while riding. I tapped into the horn wires to connect the relay. I ran the inline fuse along the frame and tie wrapped the wires. Since I have multiple things going to the battery, I had to come up with a way to connect so many wires to a single battery contact. Three is its maximum. I tried four and they wouldn't stay connected. So I merged two of the wires together into one larger one (two 18s into a single 16 gauge). I did the same with the ground wires. I wanted to hook up a junction box of some sort, but I have to determine where the safest place is to put it. Meanwhile, merging the wires is the best solution I can think of.

What does "bad boy" mean? In the UK we have the most ghastly Jamie Oliver using it perpetually whilst cooking. Is it an alternative adjective to awesome. If so I'm in favour. It's a start. Onwards and upwards

There is actually a horn named Bad Boy that is sold by Harbor Freight. It looks almost exactly like the one Dave put in his but it is slightly larger. The sound should scare the crap out of any driver moving into your lane.

Mel46 wrote:There is actually a horn named Bad Boy that is sold by Harbor Freight. It looks almost exactly like the one Dave put in his but it is slightly larger. The sound should scare the crap out of any driver moving into your lane.

You couldn't not buy it if it was named Bad Boy

http://www.harborfreight.com/catalogsea ... d+Boy+horn
Here it is. It works quite well too!