The tail light was not working. The brake light works (although for me the brake light would not work with the front brake) but the running tail light does not.
The bulb was fine, but my meter says the wires back there are not getting any juice. After taking the whole dammed scooter apart and tracing down every wire I almost gave up. I decided to look behind the horn.
SOLUTION: There is a fuse box containing one fuse and a spare behind the horn. Here's how to get to it.
Horn Box
Open the glove box and loosen the two screws.
Gently remove the badge and loosen the screw behind it.
Now the horn assembly will come loose. Be careful of the wires going to the horn.
Here's the plastic fuse box with the purple wire. There's a metal holder keeping it in place.
It was a 10mm bolt. I did not have to remove it entirely, just loosen it enough to get the fuse box out.
And here is the blown fuse with the spare. After replacing it the tail light worked again! Hope this helped.