Electrolux ESD18HRB indoor fan fluctuating

We have an issue with an Electrolux ESD18HRB Hi wall split indoor fan.
Voltage increases and decreases when on fan, heat or cool. Indoor pcb and pipe sensors have been replaced. Resistances of fan motor are steady when measured (sorry, dont have exact readings at this time) Capacitor for fan motor is on the pcb which was replaced. Removed batteries from remote, disconnected receiver board whilst running, fan still fluctuates.
No tech support for this brand over here. Any ideas out there other than burn it?