Modern Vespa

Yikes! Help, please - my wife's new Vespa has a bit of an issue...just brought it home from storage and cleaned it up to start it for her and - this happened.

I'm not sure why this happened, but here's the story:

- Bought it from overseas
- worked, but the horn was always on (button out = horn on, button pushed, horn off)
- I had a guy I knew (electrician) re-wire the horn button so it would sound only when pushed...verified it worked with the key on, but didn't start it
- brought it home, switched it on to kick-start it and the battery died quickly (so I thought - no more horn...)
- Opened up the battery compartment to give it a charge and saw the fuse casing melting (!!!)

Interestingly, the fuse did not blow...the casing just melted. Now, I don't know what that fuse was intended to do since it clearly didn't protect anything and am wondering what *should* have been inline between the battery and electrics. I'm also wondering if there was somehow feedback from the horn switch, but there is no damage to any wiring inside the switch assembly.

Any ideas on what I should do about this? Thanks!

Look around your battery holder I'll bet you find where the feed wire from the battery to the fuse was pitched.

Thanks, I never really thought of that. I suppose if it was hooked up tightly, there wouldn't have been room for an arc which is quite likely and would stop voltage from the battery before getting to the electrics even if the fuse wire is still unbroken.

I'll wire a new fuse in, making sure the connection is tight and sealed. Thanks!

If the connector on the battery side had shorted I'd expect to see blistering on the whole of the battery wire. More likely that the fuse blades weren't tight enough in the female spades.

Yup, thank you. I'm going to try to make sure the connection is as tight as possible!

i see

Put the proper fuse and fuse holder on that thing.

We all saw the sea....my first response I had to hit the just walk away button on....

Overseas, like Europe hopefully? So not a VESPA electrician, then? The circuits on these older ones make normal electricians crazy, easy to 'fix' one thing & totally bork up something else. Maybe even short out your battery somehow.

The logic of the design on these is very elusive, but the short story is they saved a couple of bucks by avoiding a voltage regulator & embraced a mysterious concept known as 'load balancing'. Many of your electrical goodies are turned OFF by just shorting them out rather than simply opening the circuit! Abracadabra, that keeps the 'load balanced'!

^^^^^ Wise words.
If your horn was originally sounding all the time you have the wrong switch fitted for a DC system. Once you have decent connections on the fuse you may find it behaves correctly and blows if you have a short further down the line.