OP
@tom_jones avatar
UTC

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Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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@tom_jones avatar
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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UTC quote
Just installed one of those loud SN air horns to my Vespa GTS 150 3v. Followed the instructions to a "t" from the scooter west website and additional websites and info from this forum but.....

every time I press the horn button, I blow my 7.5 fuse and I get no sound from the newly fitted item.

All connections are fine and fitted correctly (made myself). Also double checked with a multimeter. All fine.

Is there any electrician out there that knows a thing or two about these horns and knows the answer to this?
@roadster avatar
UTC

Molto Verboso
Kymco AK550
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Location: UK
 
Molto Verboso
@roadster avatar
Kymco AK550
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Location: UK
UTC quote
Did the air horns come with a relay? You probably need one. Is the fuse a dedicated one or a standard Vespa one? You need an in-line fuse with feed direct from the battery.
OP
@tom_jones avatar
UTC

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Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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@tom_jones avatar
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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UTC quote
Thanks for the reply. Yes. I have a relay and an in line fuse.
@miguel avatar
UTC

Veni, Vidi, Posti
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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@miguel avatar
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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UTC quote
I think the Stebel uses about 18 amps so use a 20 amp fuse. What gauge wire did you use? Can you post your wiring diagram?

Best
Miguel
@jkj-fz6 avatar
UTC

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BV400, Primavera 150, Yamaha Zuma 125
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@jkj-fz6 avatar
BV400, Primavera 150, Yamaha Zuma 125
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UTC quote
Which fuse is blowing -- the new additional one you installed with the horn, or the original fuse in the Vespa? If it's the new one you probably need a bigger fuse there, maybe 15 or 20 amps. If it's the original fuse for the horn you may have the relay wired wrong. The original fuse should now drive only the relay coil, not the horn.

Ride safe & have fun!
OP
@tom_jones avatar
UTC

Hooked
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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Location: Perth Australia
 
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@tom_jones avatar
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
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UTC quote
Thanks for the info Miguel and JKJ - FZ6.

Miguel - I have used a 20 amp fuse but with regard to the gauge wire, I have no idea. Found some random wires in my garage and used them so I'm guessing this could be the reason why it's not working.

JKJ - Its the original fuse that keeps blowing. So I will use the correct gauge wiring and if that fails then I will upgrade the fuse.

Thanks guys,

Tom.
@breaknwind avatar
UTC

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Red Devil SH150i (11,000)
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Location: Orange Park Florida
 
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@breaknwind avatar
Red Devil SH150i (11,000)
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UTC quote
Make sure your relay is wired like this. Or you will waste your time with fuses.
http://www.ado13.com/techs/relay.htm
@miguel avatar
UTC

Veni, Vidi, Posti
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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@miguel avatar
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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Location: Santa Cruz California
UTC quote
tom jones wrote:
Thanks for the info Miguel and JKJ - FZ6.

Miguel - I have used a 20 amp fuse but with regard to the gauge wire, I have no idea. Found some random wires in my garage and used them so I'm guessing this could be the reason why it's not working.

Tom.
You gotta send us the wiring diagram you used to get the best help. I know where the fuse should be but don't know where you put it.

Small wires won't cause the fuse to blow but Its possible you could cause a short and burn up some wires. You really don't want to do that.

You should be using at least a 12 gauge stranded wire on the circuit. I'm pretty sure I used 10 gauge (the wire size gets bigger as the gauge decreases so 10 gauge is bigger than 12 gauge - Don't blame me for such a crazy system). I'm presuming you use the same wire gauge system where you live. Over designing the wire size has only 1 side affect, its a bit harder to route around tight places. Cost is irrelevant.

Best
Miguel
@honkerman avatar
UTC

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Piaggio Beverly 250
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Location: Lancaster County Pennsylvania
 
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@honkerman avatar
Piaggio Beverly 250
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Location: Lancaster County Pennsylvania
UTC quote
Tbh, I've run into a similar issue but with LED lights...I'd reversed the polarity and had the lights wired backward.
@modnrod avatar
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Lambretta child
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Location: Midwest, West Oz
 
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@modnrod avatar
Lambretta child
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UTC quote
Hi Tom, me again.


We have the gauge system here too, but much more common for a non-sparky is the "Amps" rating on most of our wiring you can buy from common auto outlets. If your new horn draws 18A like some suggest, then NONE of your common looms will be sufficient or safe really.

Do you have a Jaycar store handy nearby? They have wire on the roll that you can buy at per/metre lengths, go and ask for some 30A cable. They also have inline fuses, ask them for the "yellow" wire fuse-holder, it is 30A cable, then use that cable direct from the battery to the #30 position on your common 30A 4-pin relay.
Quick relay wiring guide.......
#30 is from the battery positive.
#87 is 30A wire to your horn positive.
#86 is from your horn switch, so in this case the wire that normally went to the horn as standard.
#85 is your relay earth, the mounting screw for the relay is fine.

Then use 30A wire from your new horn negative to an earth (clean mounting point works OK), and then you are good to go.

If you are blowing your 7.5A fuse on your horn circuit, then you definately have it wired incorrectly, or you have an earth on that wire somewhere that is grounding the cct out, not good.

Any questions you can PM me, or just ask here if you want. I'm 350km north of you, so a bit far for a look, but happy to help on our local (Perth) stores.
Regards,
Dave
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
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Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
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UTC quote
MODNROD wrote:
If you are blowing your 7.5A fuse on your horn circuit, then you definately have it wired incorrectly
^^^
This.

There is no 'a' in definitely BTW.
@miguel avatar
UTC

Veni, Vidi, Posti
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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Location: Santa Cruz California
 
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@miguel avatar
2009 GTV250 (Gone), 2003 Inder trailer (also gone), 2001 BMW R1100RT
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Posts: 5707
Location: Santa Cruz California
UTC quote
Agree w Jimc. You need to show us a wiring diagram.

Bet
Miguel
@david_masse avatar
UTC

Ossessionato
2016 Vespa GTS 300 i.e. ABS sold, 2010 Vespa GTS 300 ie Super (sold) & 2003 Honda Shadow VT750 ACE (sold) & 2006 Vespa LX150 (sold)
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Location: Toronto (formerly Montreal)
 
Ossessionato
@david_masse avatar
2016 Vespa GTS 300 i.e. ABS sold, 2010 Vespa GTS 300 ie Super (sold) & 2003 Honda Shadow VT750 ACE (sold) & 2006 Vespa LX150 (sold)
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UTC quote
I'll just chime in to agree with Miguel and Jimc.

The Stebel airhorn draws ~18 amps when activated. A 20 amp fuse on that new circuit is essential and it should be close to the battery.

I used fresh 10 gauge wire direct from the battery for both positive and negative, and a relay. The OEM horn wires are connected to the relay.

A drawing of the circuit you used would be helpful.

I'm confident you will sort this out in no time.
@modnrod avatar
UTC

Addicted
Lambretta child
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Location: Midwest, West Oz
 
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@modnrod avatar
Lambretta child
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Location: Midwest, West Oz
UTC quote
jimc wrote:
There is no 'a' in definitely BTW.
Hahahaha! That would explain the "spellcheck" that I ignored! Laughing emoticon
@14perry avatar
UTC

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MP3 400 / BV250
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Posts: 3809
Location: San Diego, California
 
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@14perry avatar
MP3 400 / BV250
Joined: UTC
Posts: 3809
Location: San Diego, California
UTC quote
MODNROD wrote:
Hi Tom, me again.


We have the gauge system here too, but much more common for a non-sparky is the "Amps" rating on most of our wiring you can buy from common auto outlets. If your new horn draws 18A like some suggest, then NONE of your common looms will be sufficient or safe really.

Do you have a Jaycar store handy nearby? They have wire on the roll that you can buy at per/metre lengths, go and ask for some 30A cable. They also have inline fuses, ask them for the "yellow" wire fuse-holder, it is 30A cable, then use that cable direct from the battery to the #30 position on your common 30A 4-pin relay.
Quick relay wiring guide.......
#30 is from the battery positive.
#87 is 30A wire to your horn positive.
#86 is from your horn switch, so in this case the wire that normally went to the horn as standard.
#85 is your relay earth, the mounting screw for the relay is fine.

Then use 30A wire from your new horn negative to an earth (clean mounting point works OK), and then you are good to go.

If you are blowing your 7.5A fuse on your horn circuit, then you definately have it wired incorrectly, or you have an earth on that wire somewhere that is grounding the cct out, not good.

Any questions you can PM me, or just ask here if you want. I'm 350km north of you, so a bit far for a look, but happy to help on our local (Perth) stores.
Regards,
Dave
This is the proper way to wire air horns on a scoot.
OP
@tom_jones avatar
UTC

Hooked
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
Joined: UTC
Posts: 392
Location: Perth Australia
 
Hooked
@tom_jones avatar
Vespa GTS 150 3v SUPER. Vespa V100 x 1. Lambretta Li150 x 1. Px 125 x 2. Px 200 x 1 (red bull special) T5 Classic x 1. Vespa Cosa x 2.CF moto 650mt
Joined: UTC
Posts: 392
Location: Perth Australia
UTC quote
Ok guys, thanks for all the advice. Found out the problem, it was the faulty relay supplied to me.

Just wasted about 3 hours of my life trying to work it out. That doesn't include your time wasted too.

The seller will get shity feedback from me as a result.

On the flip side, the horn sounds pretty awesome.

Cheers,

Tom.
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