2005 Volvo S60 blower

Your problem could be a bad blower motor transistor. Next time it acts up check for power to the blower motor. To verify you need to check for power to the blower motor. To access it is on the passenger side behindethe sound proof panel. You would need to remove a black cover to access the blower motor connector which has only 2 pins. Power and ground. If you do have power then the motor is bad. If no power the transistor is bad. To replace you need to remove the blower motor and belowe it is the transistor. If you need the procedure to remove the blower motor send me a message.