Vespa Ciao - electrical problems - will pay

So I've asked this question here before, but nobody could figure it out. So I shall try again.

Out of the blue my Ciao's lights ceased to work. When I turn the light switch on, I get an extremely dim glow, and my horn wont work. When I turn the light switch to the off position, my horn blares away. The bulbs are fine, it just seems that there's something grounding that shouldn't be. I've hunted all around, it's been like this for like 6 months. The grounding wire that goes against the engine casing is a-ok.

Any ideas?

Thanks so much. If somebody helps me fix this, I'll send you money!

Re: Vespa Ciao - electrical problems - will pay

How much money do you have : ), Just kidding.

You said the red wire ground on the engine case is fastened securely, correct? Spray some electrical contact cleaner on it just to make sure it isn't corroded.

Are you referring to light switch on the handle bar? Some Ciaos also had a combo light/ignition switch on top of the headlight case.

If it is the handle bar switch have you taken it apart to check for loose wires in the switch? There are tiny little screws in the switch terminal block that hold the wires in place. Check all these to make sure a wire hasn't slipped out.

You can use some electrical contact spray to clean the wire ends and contact points. If you loosen those screws make sure they don't fall out because you may not ever find them.

When I work on the switch on the bike I hang a plastic bucket over the handle bar so it is under the switch. If I drop anything, it falls in the bucket.

You may have to replace the switch but try cleaning all the contact points first and cleaning and reseating the wires.

If it works you can send me a Million bucks.

Re: Vespa Ciao - electrical problems - will pay

Haha thanks for your comment.

I'm referring to the light/horn switch on the handlebars. The ignition switch is on the other handlebar.

I have replaced my switch completely, all screws are tightly fastened and not corroded. I even tried taking the two out and twisting them together to bypass the switch. I do get a spark - but it all stays the same. So the switch doesn't seem to be the problem.

I've cleaned all the contact points I am aware of. The one on the engine casing (black), and the connectors inside the headlight.

The only wire I'm worried about is the wire coming out of the engine casing that looks like it's coming from the magneto ... it doesn't look too hot, and when I poke my little wire tester in there I don't get a light. I'm not exactly sure what that wire is for - though it is green which is usually ground - so I wouldn't get a charge anyways.

Thanks for your help

Re: Vespa Ciao - electrical problems - will pay


I'm a vespa bravo owner myself which I recently purchased from my sister. At first it didn't start well but after fiddling with the carburetor and air box, it now runs fine.

At some time in my fiddling process, I completely took the motor out of the frame and after reassembly my lights wouldn't work anymore.

Symptoms: front light only working when using my brakes, and even then dimly. Horn just barely audible.

Solution: After almost seizing my brain from looking at the electrical diagram, I understood that during reassembly, I had connected the red and the black wire to the wrong connector on my motor, red to black and vice versa.

I don't know if your problem could be as simple as that, but to me it sure sounded a lot like my problem.

My problems are solved now, apart from the leaking carburetor that I refuse to open up once more and the front stationary light which blew not 1 mile after installation...

Re: Vespa Ciao - electrical problems - will pay

Wow that sounds somewhat familiar. At one point in time my headlight was only coming on dimly when I pulled the brakes, but not anymore. Though as far as I know, there's only a black wire that plugs into my engine - the green one goes straight into the engine itself, no plugs or anything.

When I get home I'll take a look at it. Thanks so much!

Re: Vespa Ciao - electrical problems - will pay

I was wondering, did you download the manual ? There you should be able to find the wiring diagram for your ciao.

In my case I had to look at page 21. (but there's no green wire, so yours probably is different.) I'm pretty sure that black is ground though.

Re: Vespa Ciao - electrical problems - will pay

Don Pflueger /

hmmmm. sounds simple. after reading thru this thread, i have some ideas.

my first and simplest idea to check are the bulbs, their sockets, and electrical connectors. it sounds to me more like a resistance somewhere rather than a ground issue. make sure every one of those connectors is clean, shiny, and brass colored (unless it has silver colored connectors).

also make sure the connectors on the horn are good and clean as on a lot of bikes, the lights wont work unless the horn does. check the horn for ohms. how much resistance does it have? just cuz it works when the lights are off doesnt mean its good.

i'm not sure if the ciao has this type of setup or not, but some peds have a resistor built into the tail light housing. look in the service manual to see where its at on a ciao. the resistor keeps the head and tail light bulbs from blowing at high revs. test it with an ohm meter. the service manual should give you the values you need.

most times i would start here, but since ciaos are such pos bikes and the magneto is such a pain to get to i left this for last. test the wires coming out of the stator with a volt meter to ensure you have the correct voltage and wattage. pull the engine, remove the flywheel, and check to see if the charging coil in the magneto has and rust on its pick ups, or its base where it mounts to the engine block. a little bit of rust can impede the magnetic properties of the charging coil as the magnet passes over it as the engine runs. do an ohms test on the coil to check its values. if the gold colored film is damaged or the wrapped wire is exposed, your coil cant work properly as it is shorting out inside itself. clean the magnets inside the flywheel.

electricity flows like water. it has a starting point (the charging or lighting coil in the magneto) and an ending point (which is where the charging or lighting coil is grounded to the engine block). and as long as you have a good clean flow everything should work fine.

Re: Vespa Ciao - electrical problems - will pay

Yeah, I've got the Haynes manual, which I checked out the wiring diagram - but don't really understand what to look for.

Re: Vespa Ciao - electrical problems - will pay

Awesome, thanks for the reply. I'll go buy an ohm meter, some electrical connector cleaner, and try to find the resistor.

I've never used an ohm meter before, and just to double check before trying blind - to, say, test the horn - what do I do with the ohm meter?

Re: Vespa Ciao - electrical problems - will pay

Don Pflueger /

an ohm meter measures the amount of electrical resistance that an item has. in other words, i measure the amount of force needed to push the electricity thru that item. a good example is speakers. home stereo speakers resist up to 4 ohms while car stereo speakers resist up to 8 ohms.

your horn may be rated at 4 ohms resistance, but if its bad, it may be requiring more current to be forced thru it. i hope i described that right.

a resistor is used in a bikes electrical system to regulate the current produced in the magneto so that bulbs dont blow. it actually onlly allows so much current to travel at one time. every moped has some type of resistor built in somewhere whether it be a voltage regulator, or just a simple resistor. its been a few years since i got rid of my 3 ciaos so i cant remember how they are wired up off the top of my head. but, their electrical systems are very simple.

read the service manual you were given, look closely at the wire diagram, and you will be able to figure it out. and you'll gain very useful knowledge in diagnosing a motorcycle electrical system.

Re: Vespa Ciao - electrical problems - will pay

Okay I went and picked up an ohm meter, I was hoping it was going to look a little easier to understand. This is what I bought

So let's see ... from what I can tell, I plug the black wire into the COM port, and the red into the Fused port and turn it to 200 Ohms. To test the horn, which wire do I touch with each side? Does the engine need to be running?

I apologize if I'm a moron about this - I've never done this before. I appreciate any help, and will try to compensate you as much as I can.

Thanks again,


P.S. If you find it easier to talk on the phone, I'm more than willing to do that. I can call you to save you charges. If you'd rather do this, email me your phone number at my email


Re: Vespa Ciao - electrical problems - will pay

Don Pflueger /

you have to disconnect each item to test it. put the meters leads on each one of the terminals of the horn or whatever item you test. you need to read the service manual to find out what values you need to set the meter at.ohms are measured kinda like the metric system, in tens, hundreds, and thousands.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account