OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
Hi folks!

Just bought this Vespa 100 Sport small frame:

External inline image provided by member with no explanatory text

The bike has a ducati flywheel and CDI installed by a local shop, no battery, so hardwired. The horn works intermittently. I removed the horn to make sure it was plugged in, it looks fine. Sometimes it works and is really loud. I don't have a socket to get off the nut on the front of the horn, but I tried messing with that screw on the back, but I can't tell if it's an adjuster or what.

Does anyone know about these horns and whether they need to be cleaned or something every so often?

Thank you!!
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special,, 2015 HD Road Glide Special
Joined: UTC
Posts: 5258
Location: Oceanside, CA
 
Veni, Vidi, Posti
@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special,, 2015 HD Road Glide Special
Joined: UTC
Posts: 5258
Location: Oceanside, CA
UTC quote
Make sure the electrical contacts on the horn and coming off the harness are clean and tight. I used sandpaper and electrical contact cleaner. If that doesn't solve it do the same thing with the metal contacts in the thumb switch.
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
Hi Folks,

I checked the terminals and they look pretty good. I visited SF Scooter Center and Diego (who worked on the bike when the previous owner owned it), told me that when a bike is hardwired, with the battery removed (ie converted from DC to AC) the original horn will never work, it's a DC horn or whatever and can't work with AC. He also said there's no other horn that fits the small frame, and you just gotta do without.

That true?
@sdjohn avatar
UTC

Johnny Two Tone
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 9004
Location: San Diego, CA
 
Johnny Two Tone
@sdjohn avatar
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 9004
Location: San Diego, CA
UTC quote
Diego is awesome, he will not steer you wrong. DC horns wired AC are intermittent at best.
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special,, 2015 HD Road Glide Special
Joined: UTC
Posts: 5258
Location: Oceanside, CA
 
Veni, Vidi, Posti
@mjrally avatar
73 & 74 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special,, 2015 HD Road Glide Special
Joined: UTC
Posts: 5258
Location: Oceanside, CA
UTC quote
Oooohhhhhh!!! You forgot to mention you didn't have a battery. PM sent.
@drona avatar
UTC

Molto Verboso
59 Vespa, 65 Vespa, 66 Vespa, 57 Vespa
Joined: UTC
Posts: 1322
Location: Portland Oregon
 
Molto Verboso
@drona avatar
59 Vespa, 65 Vespa, 66 Vespa, 57 Vespa
Joined: UTC
Posts: 1322
Location: Portland Oregon
@coady avatar
UTC

Enthusiast
1976 Rally 200, 1979 P200e
Joined: UTC
Posts: 78
Location: Eureka, CA
 
Enthusiast
@coady avatar
1976 Rally 200, 1979 P200e
Joined: UTC
Posts: 78
Location: Eureka, CA
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
Can anyone recommend to me a diode I could buy to run in line with the + wire?

Thanks!
@drona avatar
UTC

Molto Verboso
59 Vespa, 65 Vespa, 66 Vespa, 57 Vespa
Joined: UTC
Posts: 1322
Location: Portland Oregon
 
Molto Verboso
@drona avatar
59 Vespa, 65 Vespa, 66 Vespa, 57 Vespa
Joined: UTC
Posts: 1322
Location: Portland Oregon
UTC quote
Did you read the thread I linked?
Also.. use the search feature.
⬆️    About 5 years elapsed    ⬇️
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
dr.ona wrote:
Did you read the thread I linked?
Also.. use the search feature.
Resurrecting this thread. I visited the thread linked by this poster and ironically the original poster there complained that people were steering him in a dozen directions hahaha.

So what's the real word here??

Rectifier? Where do you mount it?

Replacement horn? Do they fit! Do they burn up?

Diode? Do those fail?

Thanks
@sdjohn avatar
UTC

Johnny Two Tone
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 9004
Location: San Diego, CA
 
Johnny Two Tone
@sdjohn avatar
'15 GTS300, '86 PX125EFL, '66 VBB, '01 ET4
Joined: UTC
Posts: 9004
Location: San Diego, CA
UTC quote
yeah just get an ac horn (buzzer). even if you have 12v, the 6v ac horn will work, you only use it quickly anyway. that's how I did my Primavera and it's been all good. it isn't something you use every day anyway, and if you do well then you might want to work on some anger management issues Razz emoticon
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
sdjohn wrote:
yeah just get an ac horn (buzzer). even if you have 12v, the 6v ac horn will work, you only use it quickly anyway. that's how I did my Primavera and it's been all good. it isn't something you use every day anyway, and if you do well then you might want to work on some anger management issues Razz emoticon
Can you give me a link to the type you're referring to?
@socalguy avatar
UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
 
bodgemaster
@socalguy avatar
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
Whoa!! Thank you! How come no one's mentioned this before I wonder.

Is this the one you have? And it fits into a small frame and works?
@socalguy avatar
UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
 
bodgemaster
@socalguy avatar
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7223
Location: So Cal
UTC quote
Yep
Forum member supplied image with no explanatory text
OP
@akpasta avatar
UTC

Hooked
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
 
Hooked
@akpasta avatar
1980 Vespa 100 Sport
Joined: UTC
Posts: 144
Location: San Francisco
UTC quote
SoCalGuy wrote:
Yep
Awesome! Gonna give it a try!
DoubleGood Design banner

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Buy Me A Coffee
 

Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com


All Content Copyright 2005-2025 by Modern Vespa.
All Rights Reserved.


[ Time: 0.0155s ][ Queries: 6 (0.0056s) ][ live ][ 323 ][ ThingOne ]