Modern Vespa

While driving my vespa 250 for about 100 yards, all my electric power shuts off. After about 1 1/2 min the power comes on and I can restart the engine. Then drive it another 100 yd and power shut off all over again. I have replaced the battery and its fully chaged and I have checked the stator connections and it work fine. I noticed that the main fuses get hot to the touch after about a minute of idling. Any ideas how to fix this issue?

I’d start by pulling all the fuses and cleaning their contacts.

I've cleaned all the fuse connectors and it still shut off with no electrical power.

I suppose you cleaned the battery terminals too?

It seems like I trip a circuit breaker that turns all my power off then after a minute and a 1/2 it reengages. Is there a sensor that would cause me to lose electric power? I electric power lose is the same as if I undid the battery. All the connections to the battery are tight.

As far as I know there are no circuit breakers or resettable fuses in a Vespa. I’m thinking there’s a dirty or loose connection that gets hot (but not enough current to blow a fuse) and opens up (goes to high resistance).

Does the power cut out only when the scooter has moved 100 yards, or also when it’s just idling on the stand? (Is vibration involved?)

Could be a bad battery. (Internal connection.) Have you tried a new battery?

At 1st I thought it was the battery so I bought a new one and have new clean connections. The power shut off when it's on the stand idling after about 2 minutes. I don't think it's the distance I go, I think it's how long the scooter is running.

I’ve seen short circuits in light bulb sockets. That’s all I can think of for now.

Just replace the fuses, maybe? (Maybe a fuse has a hairline crack that opens up when hot?) Fuses are inexpensive.

Thanks for your help. I'm going to go back and clean all the connections again. I do think something is expanding and then when it cools down it reengages.

Bad voltage regulator?

That a fuse gets hot in just a minute is a huge clue. Clean the contacts thoroughly, check the crimping of the wires to the contacts, and replace the fuse with a new one. OK, 'new' doesn't mean tested, but doing all that will prove one way or another what the problem is.

Me, before doing all that, I'd first clip a voltmeter to the battery, and another to the other side of the fuse that gets hot. Then do the idling test. If one side reads >13V and the other reads a different voltage, then that will convert the guess into a certainty.

I'll definitely try that as soon as I get home from work