Modern Vespa

I went with the Fiamm RoadThunder. It's no air horn, in fact it's name is a bit of wistful thinking: it's about as loud as a Volkswagon (and sounds very similar), but far louder than the stock (I realize that's not saying much) and had the huge advantage of drawing low enough current as to operate without adding any relay or new wiring. <http://www.ridesafer.com/Fiamm_RoadThunder_Horn_p/h0009.htm>

That being said, of course everything I do with the MP3 seems to wind up more complicated than I first thought. This horn has an external diaphram, like the stock horn but it's slightly bigger. When I tried to just swap it out, it wound up contacting the tupperware grille and just made a buzzing sound. Imagine a speaker playing and you pushed your finger against it; same idea. I could find nowhere in the general area of the original horn that it would fit without contacting SOMETHING, including facing it backwards. The only way to face it backwards was to drill a hole for the mounting screw in the tupperware, so since I now had a useless hole...I decided to mount the horn externally. I have heard some people criticize these external diaphram horns as being affected by repeated exposure to water, but I'm a fair weather driver so I don't anticipate any problems. No one will mistake me for a diesel locomotive, but it's more than loud enough to be clearly heard and I didn't have to run multiple relays and new wiring. It's also more than loud enough to pass my state inspection, which I have absolutely no doubt the stock horn would fail. That's a major issue for me with Piaggio: the stock horn is neither safe nor, at least in my state, legal.

One thing I would suggest for anyone considering this style of horn (in other words, a larger & louder version of the OEM horn): I see there are horns that have a metal grille in the front to protect their diaphrams from contacting anything (I admit that I saw these when shopping for the Road Thunder but I didn't realize the cover was functinal, I thought it was just decorative), and so long as you watch the amperage (the /500 horn fuse is 7.5 amps, while the Fiamm pulls only 4 amps) you'd be okay and might even be able to stuff it under the tupperware. Or you could always run wires...

...on the other hand, if you're okay with mounting it externally, the RoadThunder is definitely louder, definitely pulls low amps...and definitely works.

Thanks! I will look into this puppy!

Very interesting Jeff....Do you happen to know if this horn would work on the 250 as well? I'm not talented electrical wise...but if it's a basic kinda job..maybe. Yours is exposed to the elements...is there any kind of cover to protect it...maybe by improvising. The horn on my Shadow is exposed (I placed it on top of the chrome radiator grill with a chrome slotted cap......it still beeps (I too am a fairweather rider...so far anyway).

FYI the MP3 250, 400, and 500 at use the same horn part # 58033R-1. How did you measure the current draws on the stock and aftermarket horn?

Nice installation if it stays clean enough to keep working. One might be able to fashion a grill to go over it. I'm an all weather rider so not for me. Also I already have a Stebel installed. A horn is the first and most important safety mod to consider.

Curious on your state laws.
Do scooters / motorcyles get regular state inspections?
Is the horn part of the inspection?
What is the standard for the horn that the Piaggion one may not pass?
How do all the Vespas on the road pass if these are requirements?

[quote="14perry"]FYI the MP3 250, 400, and 500 at use the same horn part # 58033R-1. How did you measure the current draws on the stock and aftermarket horn?[/quote]

1. Frankly I didn't, I relied upon the manufacturer's claims on their web site. Yes, I certainly could have done a direct measurement with an dedicated ampmeter (and there's a trick way to use a voltmeter with a parallel resistor that basically makes it a ampmeter) but I was just looking for ballpark. Besides, to measure the draw I would have had to already bought it. I know the fuse is 7.5 amps, that fuse services several items and each one has to be protected so that tells me two things: first, the wiring to the horn must support at least 7.5 amps; and secondly, no one component actually pulls that much because the fuse must be able to handle all of the components at once. It looks like the horn is the only item on that fuse that is potentially high-drain.

2. As to weather: as observed, motorcycles almost ALWAYS use this kind of horn, externally mounted (although usually higher up on the frame, but the splash guard on the MP3's front wheels work really well). I was not suggesting in any way that the horn is NOT waterproof, I was just addressing some objections I have seen elsewhere on this forum, which may or may not be justified.

3. You could fashion a grille, or you could simply buy a similar unit that already has its own grille. Because I didn't appreciate the diaphram interference issue, I was looking only for "loud" and "low amperage" and did not really take a look at those units.

4. A. Do scooters / motorcyles get regular state inspections?
Is the horn part of the inspection?

OMG, that's a whole thread right there. New Jersey is one of two states (I understand Indiana is the other, any Hoosiers can confirm or deny) that has no intermediate category of motorized bike. There are mopeds - less than 50cc and can be pedaled - and there are motorcycles. That's it. An 80cc scooter is treated exactly like a 1500cc Harley; indeed, outside the MSF courses, practically nobody takes their road test on an actual motorcycle, everybody does it on a rented 80cc scooter because you're virtually guaranteed to pass. It's an embarassment and an in-state joke.

So this means that the 80cc scooter goes through the same inspection as everybody else. The good news is that new vehicles are exempt from inspections for two years, and vehicles meeting certain emission standards - including scooters and hybrid cars - get a pass for four years (when purchased new; used vehicles must always be inspected within 30 days).

B. What is the standard for the horn that the Piaggion one may not pass?

Clearly audible in traffic 200 feet away (subjective per inspector, no objective measurement criteria i.e. a decibel meter). I failed for a dying horn in a pickup truck that was subjectively still many times louder than the MP3. I don't think the MP3 horn can be heard 20 feet away!

C. How do all the Vespas on the road pass if these are requirements?

I admit I have never driven a Vespa, so I cannot comment on the general loudness of their horns...but I have driven plenty of scooters on vacation. None of them have had as wimpy a horn as the MP3.

I went with the high tone and low tone fiamms. http://www.ridesafer.com/Fiamm_Dual_HK9_High_Performance_Horns_Kit_p/h0013.htm

These do require a relay but installation was not that bad. Hardest part was finding a place to mount.

You may want to move yours "indoors" in one of the positions mine are in. Will help to keep it cleaner i would think.

[quote="stickyfrog"]I went with the high tone and low tone fiamms. http://www.ridesafer.com/Fiamm_Dual_HK9_High_Performance_Horns_Kit_p/h0013.htm

These do require a relay but installation was not that bad. Hardest part was finding a place to mount.

You may want to move yours "indoors" in one of the positions mine are in. Will help to keep it cleaner i would think.[/quote]

Very nice Sticky. I had a specific criterion, which I suspect would be shared by others: I didn't necessarilly want an extra-loud horn(s), I just wanted a horn that at least met the basic state (and common sense) requirement that it be heard. If I could do so without any re-wiring relays etc, that was a plus.

According to the site selling them the RoadThunder (134dB @ 4") is louder than the Dual HK9 (125 dB @ 4"), maybe I'm reading that wrong... do they mean 125db x2. I also like the idea of not having to mess with the electricals.

Yes i just looked and the road thunder is louder. not sure if if x 2 makes the dual louder though...any sound experts here?

It really wasn't that hard to set up though, ran a 12 guage wire (fuse protected) from the battery to the relay (mounted under the windscreen) and then from there to the horns. Ran a smaller wire from the horn button to the relay and grounded the relay of course. The fiamms only sound when the horn button is pressed. Also, i know have a separate power supply for future mods.

But no doubt the other horn would be easier as long as the amperage stated is actual. I think, not sure what the max amps is on the stock horn rig. I would still put it inside though like I did the duals.

>I think, not sure what the max amps is on the stock horn rig.

Stock horn pulls 2 amps at 12 volts. Manufacturer's site: <http://www.leb.it/lebgb/framegbavv.htm>. The stock horn is the K70 (I've got one in my hand and am reading the number off it). Claimed 108dB at 2 meters - I seriously doubt it. In theory, I could have left the original horn and ADDED the Road Thunder and still had an amp or two to spare. But replacing a 2A horn with a 4A horn, I went from 5.5A available (remember there are other things on that fuse: ECU, parking lever, instrument panel, headlight remote control (what?), and antitheft (okay, I'll concede it's unlikely that the antitheft and the horn would ever pull current simultaneously)) to 3.5A available, a reduction of (5.5-3.5)/5.5 = 36%.
If I'd hooked both horns up together, that would mean going from 5.5A available to 1.5A available, a reduction of (5.5-1.5)/5.5 = 73% reduction in current remaining for other things. So maybe it's best I just stuck with a single, louder horn.

Besides, Gary Sinise wasn't available to run the tests for me (geek pop reference).

P.S. before somebody orders the RoadThunder and complains it won't fit: the RoadThunder has wider, but not thicker, spade connectors than the stock. I could have cut the female connectors off the horn wires and soldered them or crimped on new connectors, but I decided to do something much more destructive. Using diagonal cutters, I snipped off several millimeters of the RoadThunder's spade lugs. They're copper alloy and they trim down easily. Now the original horn connectors, with the original horn wiring still attached, fit right onto the RoadThunder. Since they're now external, I fitted an inch of shrink-wrap around them and shrunk it down tight, preventing the connectors from coming loose and hopefully making the connection a bit waterproof.

Okay, the issue that no one addressed is the horn button itself. Yes the fuse is 7.5 amps the wiring supports the amperage for the horn and what ever is tapped onto that circuit. But what of the contacts on the horn button itself? If its designed for the stock horn and you increase but keep it under the fuse rating what are you doing to the longevity of the horn contacts? A relay draws around 150milliamps the switch will last forever. Even if you add a relay for the fiamm use the stock power for the relay(ie no new power to battery) you will increase the life of the horn switch. DO NOT DO THIS WITH AIR HORNS!!!! ALWAYS RUN A HEAVY FUSED LEAD TO BATTERY
Additional note:
On the 500, 400, and 250 the blue wire from fuse # 9 feeds the horn button and the Hi/Low switch to the headlights, so if you increase the horn draw,change the bulbs wattage you could weaken and pop the fuse down the road. Preferably not a dark one

Well Perry, that's a good point. Clearly the horn button is rated for more than 7.5 amps because if the horn circuit was shorted and you hit the horn the fuse would have to fry before any component along the path, but as you correctly observe that just means the button won't melt, not that it won't deteriorate sooner. Typically MTBF for switches is calculated at full load, so a 15A switch with a MTBF of 20,000 cycles is demonstrated to do exactly that. The problem is we don't know what the MTBF for a component like the horn button is (or even what the maximum load is); it could be, for example, 1,000 cycles at 10 amps which would be unacceptable but a million cycles at 2A. The component is Piaggion dwg. no. 638976, but without a manufacturer's cross-reference I don't think this debate can be resolved.

Of course, I would say that horn buttons and the like are typically vastly overengineered and would long outlast the life of the vehicle...but what I keep hearing about MP3 turn signal switches makes me a bit skeptical.

As you see with my additional note the 7.5 amp fuse is for the horn and the headlights so in theory the switch doesnot see the full load so its rating may be less. And given the problems with turn signal switches I wouldnot increase the stress on any electrical component. I think some Lucas engineers moved to Italy. Why do the English drink warm beer? They have Lucas refrigerators! I hope my 400 doesn't turn into a three-wheeled FIAT Fix It Again Tony

>As you see with my additional note the 7.5 amp fuse is for the horn and the headlights so in theory the switch doesnot see the full load so its rating may be less.

Well it shouldn't be, but I don't know the European requirements. In the U.S. electrical systems adhere to NEMA and the requirement is for a fuse to blow before any one of its protected circuits in event of a full short. That would mean that the horn button would have to be rated greater than 7.5A (because otherwise if the horn were to short then it would be the button that would melt first). Since that's just common sense, I imagine the Europeans have a similar requirement, but I cannot say objectively.

>And given the problems with turn signal switches I wouldnot increase the stress on any electrical component.

The MP3 has (at least) one serious design flaw: tracing the master wiring schematic, it turns out that the horn does have a relay (the "klaxon remote control"); but the relay provides power to the button instead of the other way around. I realize why Piaggio did this (because the horn is also used to sound alerts in the event of a hydraulic failure) but the horn button and the hydraulic sensor circuit could have been wired in parallel to the relay input. Of course this still wouldn't allow an air horn to be connected because of the substandard wiring so I guess from their viewpoint it didn't matter. Still, this is what creates the issue that Perry is on about, that the full load of the horn is carried by the button (so increasing the horn amperage increases the load, and ultimately the wear, on that button).

For me, the trade between a possibly shortened button life and having a louder horn - that might quite possibly save my life - without having to install relays and run new wiring was a no-brainer. But Perry does have a point. In any event, I certainly would not install a horn greater than 4A (twice OEM) and I would not connect both the new horn and the old one together, based on the logic Perry presents.

One would think that a $10,000 motorcycle would have wiring and switches superior to a $800 Tiawanise moped.

I am pretty much lost in this wiring thread, but having Stebels in both my 500s I had issues with one ( mechanic did not wire a relay) and it blew fuses ( this did not happen at first, it took a while-like months).
Bottom line, and I am sorry to not remember exactly now, but if the horn fuse blows ( not vital for the bike to at least run), it also seemed to take down along with it things that were important--like I think the digital display.
Thats the main thing I recall. there could be more.
Now there is an inline fuse so it doesn't happen that way again.

Did you notice it has layers? These help immensely. It's also one of the best m/c wiring diagrams IMHO.

[quote="jimc"][quote="rjeffb"]The MP3 has (at least) one serious design flaw: tracing the master wiring schematic, [/quote]
Did you notice it has layers? These help immensely. It's also one of the best m/c wiring diagrams IMHO.[/quote]

Yes, although the systems descriptions are all in Italian! Can't have everything...

Now that I found the right layer (thanks Jim) and re-traced in color, I see that I misspoke: the horn button is not fed by the horn remote switch, it is fed by the #9 (on the /500) fuse, and the horn relay feeds power to the same connector on the horn. The reason for this is so when you hit the horn button, you are not also feeding power backwards into the hydraulic sensor circuit (because it is normally interrupted by the relay). Nonetheless, my comment on how it could have been wired instead still stands and is indeed how most car horns (e.g. a car that uses its horn both for driving and as its burglar alarm) are wired.

Im confused. Can I install this roadthunder horn with out messing my scooter or not? I don' know anything about amps and relays.

>Im confused. Can I install this roadthunder horn with out messing my scooter or not? I don' know anything about amps and relays.

Fair enough. Yes you can, but since this horn pulls more current than the stock, it may - or may not - reduce the overall life of the horn button. On the other hand, it will work, and it will not melt any wires or blow any fuses.

The main thing to be aware of is that this particular horn cannot be mounted internally as a direct replacement. Either you will have to a) mount it outside like I did, or b) mount it under the dash and run some wires. I choose (a), but the main reason I did it was I thought it would be a direct replacement so I had already committed myself. Here's what I did:

1. Remove the screws along the underside of the front left wheel well. There are some other screws hidden near the centerline of the trike as well. It will be difficult to get them all, but the more you remove the easier a time you'll have. Frustratingly, the screws are different types and lengths, so keep track of which one came from where. Also, the speed nuts along the centerline are essentially inaccessible by you, so go slowly and deliberately when removing or inserting any screws not right at the wheel well lip.

2. Pry the wheel well lip apart and reach in to unplug the wires from the horn (behind the grille). I went through the trouble to actually remove the old horn, but that's because at that point I still thought I was going to just swap them. Also, watch out for the speed nuts - the MP3 relies on these el cheapo sping clips instead of nuts, so as you are doing this check that each hole is still covered by a speed nut; if not, look around and find it because it no doubt slipped out and fell.

3. It's a pain to remove the old horn without some more serious panel disassembly, so you may consider just leaving it there. Alternatively, you could wire up both horns, but then as has been pointed out you will be drawing more than half the total rated current and that is probably not a good idea for the longevity of your horn button.

4. Drill a hole in the tupperware to mount the new horn to. You want it close enough to the old horn location so that the wires will reach the terminals as-is. Dill another hole slightly above that one to run the wires through (yes, I know it's not watertight. Big deal, neither is the existing horn grille).

5. Either cut off the existing connectors from the horn wires and crimp on some correctly sized connectors from Radio Shack, or take a pair of diagonal cutters and bite away a sliver of the new horn's terminals (they're brass and cut very easilly) so that the original wiring connectors slide on.

6. The new horn comes with various brackets. You won't use any of them, but you will want a lock washer in front of and behind the tupperware, plus you should have a flat washer behind to distribute some of the tightening force.

7. Optional but highly recommended, slide a length of heat-shrink tubing over both connectors and down the horn wiring. When finished, this will help keep the connectors secure and dry.

8. Run the horn wires through the top hole and connect to the horn. Turn on the trike and check that the horn works.

9. Optionally, push the shrink tubing back down over the connectors and use a match to shrink them down securely.

10. Mount the horn into the lower hole with lock washers, flat washer, and nut.

11. Remount the various screws, but first, take a quick look around and make sure all the speed nuts are still there.

According to a recent "review"* of the MP3 Hybrid, that new vehicle has a new horn.

<http://www.motorcycle.com/news/2010-piaggio-mp3-hybrid-introduced-88520.html>

*although supposedly hybrids have been on sale for several weeks, to my knowledge nobody has posted an actual hands-on review, which strikes me as rather suspicious...

This is the purpose for which diodes exist - current flows only in one direction through a diode. I don't understand why they would not be employed here since they are used in virtually every other DC based machine, and especially marine craft. Still, they must have a reason - right?

On a side note (pun intended!) I have my Stebel installed and functional now and utilized yesterday while on the interstate - in heavy, heavy traffic and 100+ degree heat. There were many toy haulers returning from the weekend at the dunes (etc.), mini-vans full of kids and sidetracked parents on their phones, tractor-trailers, gonzo kids in their drifter machines, blah, blah, none of them intent on the road and all seemingly distracted. I had no compunction about using my horn to ensure my presence was noted... I would say it is hear maybe 70% of the time, maybe mostly due to loud stereos in use and just remarkable wind noise. Still, the stock horn would be pathetically useless in this situation so no contest - the Stebel is a requirement, imo.

My Stebel is installed with the independent, engine power on only relay wiring and extra fusing as has been detailed elsewhere in this forum, and I am very grateful for the efforts put forth by others in having done that - it has been enormously helpful.

If you knew how much trouble a handful of diodes caused on the X9 500SL you'd be bloody grateful Piaggio now use so few of them, and only in places where they are easily accessible.

Anyway, in this case the tilt-control unit (presumably with small compact semiconductors) needs to switch the horn - a much larger current than one suspects the semiconductors would wish to switch, plus loads of reactive spikes - and if the horn was faulty could render the whole unit inoperable. A perfect use for a cheap standard relay.

Well then I'm bloody grateful to not have that kind of problem. Still seems odd given their common use elsewhere, but I never fix things that ain't broken. Well, almost never. Sure seems that way since the simple relay for the new horn installation works well, and the 'meep'meep' is still ready to sound should the tilt control unit signal it to do so.

I also added a light control system for my turn signals and new running lights which I will detail elsewhere when time - I wonder what you might have to say about that when you see it...