Radio Shack sells a spray can of contact cleaner (TV tuner cleaner) that cleans away an amount of crud and oxidation that has a way of building up in switches and electrical contacts that might cause situations like poor lights, etc.
It's not cheap, but if you are careful with how you squirt it it can last a long time.
It easily penetrate switches and contacts and lubricates them against future corrosion without taking things apart, taking only a few minutes to do its job.
If you leave the scooter outside or in a damp area and are having electrical problems this might be a thing to do once a year.
