Could be the stator or the rectifier or I believe there is a fuse in the circuit. So check the fuse first.
Easy way to tell is start the bike. Check to see if you have 14.5v or around that at the battery if not, unplug the 3 wire stator connectors. Set you meter to AC voltage and see how much AC volts are coming off the wires. If you not getting any I would ohm the stator out just to make sure before you condem it. If you are getting good AC voltage there and ohm reading is good I would make sure you're connections are good and at the rectifier. Ohm reading for the charging side is .7-.89 ohms.
If the stator is good and the connections are good, you can even check for AC voltage going into the rectifier and you have no DC current coming out of the recitier then you know it's bad. You could also do a diode test on the rectifier but if all other things are ok then you know it is bad.
hope this helps.
