hi mate,electrician on the job,let’s see wot we can help you with!
as mtl said it definately sounds like a bad earth prob,cos you have lost all power.however,you could also have a problem with the regulator but that’s quite rare,but not impossible.remember as i told the lad with the 50 special vespa lighting electrics are ac (alternating current) and your starter circuit is dc(direct current).the two don’t mix.
is your starter circuit working ok? or has the battery gone flat?
if the batt has gone flat then i think you should be looking at your main frame earthing or regulator,because it has obviously affected your charging circuit.if the engine is turning ok,without any noticable loss in power,then i think you may have an earthing problem on the main wiring loom.is your horn working ok? the reason i ask is because on some pure ac models with the „duck“ type horns all current goes through the horn first.i havn’t studied the newer wiring diagrams enough to work out if they have a similar design! sorry!
remember on an ac system if you have a cable chaffed down to earth there are no fuses to b***,so all that happens is the power takes the easiest route back to the stator,ie down to earth through the frame thus bypassing the lighting and power circuit.
another thing to remember with vespa electrics is the engines’ power is generated seperately to the lighting and power,so just because the bike runs ok it dosn’t mean your lighting coils arn’t knackered!
so you could also have a fault on your stator,probably a dry joint if you have a lack of power.
electrics can get a bit complex,so if you try all of this to no avail post another note with your email and we can get in touch and have a bit crack over the fone!hope this helps