I just replaced the control board because the relay that controlled the blower motor was faulty. That solved, I'm trying to determine if the blower motor needs to be replaced. When I serviced the roof top package - cleaning both coils, new filters and replacing the blower fan belt. When I had the belt off I spun both the blower and motor by their respective pulleys. They both spun freely and smooth. When the motor is running it is not close to the RPM that is listed in the book. Is there anything that would cause this other than a motor that needs to be replaced. All voltages are within 10% of 115/230V.