Modern Vespa

Have piaggio mp3 500 model 2021. The battery drained and I connected by mistake ( idiots mistake ) 24 v battery to start. I thought it was 12 .

The piaggio works and drives 60 mph. but the MIL engine light is on. And the reverse DC will not work.

Any ideas?

The piaggio has only 300 mile on it.

What an idiot.

Check all the fuses first and then expand from there. Allot of electrical issues on MP3s are either battery or fuses. There is the main fuse panel under the seat, one on left side foot rest (at least on the 2016 serie) and a hidden fuse near the starter under the storage compartmen. If those are good then things can expand from there to get more complicated.

The engine MIL light disappeared.

I checked the fuses and they are good. Thank you for the reply !

Dodged a HUGE bullet there with that one.

I am not sure i am 100% out of the woods . lets see how this will look like in the near future.

you are Absolutely right -there could be multiple things that could go really wrong.

it was a dumb mistake .

Just a guess that you could burn your voltage regulator which causes CEL while the voltage it provides is too high.

I think it is running now ok. All the lights OFF .

Thank you for your input - yes the voltage regulator could have collapsed with so much voltage. I am lucky it didn't .

I wish it was fuse protected so that fuses got burned but I connect 24V and no fuse dies. I think it's bad protection from the fuses side.

Remember that fuses only protect electrical circuits against excessive current draw i.e. Amps by the electrical consumer.

No amount of fuses will help protect against excessive input voltage.

And also be very wary of cheap Chinese or fuses (example: don't buy automotive stuff at the dollar store). Many of those are not correctly manufactured and/or rated and are a safety (fire) hazard.

As I said, you got away with murder OJ style once. Don't push your luck on substandard parts.

These two websites are your best friends if you need to do some light work on the bike to replace something. The parts diagrams and lists are supremely useful when trying to figure out how big a job is and its associated costs.

Must make sure you know EXACTLY which sub-variant you have. Once I ordered a replacement brake handle only to learn that it did not fit my particular sub-variant so had to re-order a different one that did. Same bike, same model year, same color, same engine, just the exact trim was different.

Parts Diagram for EasyParts (site has an English mode) for the Voltage Regulator.
https://www.easyparts.nl/explodedview/Genuine-parts-Piaggio-MP3-500-HPE-Sport-ABS-E4-2019-2021-(NAFTA)-Regulator-Coil-m33729-d227580

Official Parts Piaggio diagram and parts catalog.
https://www.parts-piaggio.com/piaggio-scooters/500-PIAGGIO-SCOOTER/MP3/2021/MP3-500-Sport-Advanced-Euro-5/Impianto-elettrico/Voltage-Regulators--Electronic-Control-Units-ecu--HT-Coil/1564/39/21202/3113