it will be the regulator rectifier that is at fault,piaggio in their infinate wisdom decided to combine the indicator relay and the regulator rectifier in one unit,it is under the rear seat cowling on the left hand side ,fit a new one and i bet its ok they always go wrong,if you want you can just pull the two relay wires out of the multiplug connector and fit a normal relay to it i think the wires are the two at the back and it may be purple and brown or something like that.
adam bike doctor (of milton keynes motorcycle centre), February 2011