The furnace motor is attached to the blower wheel and the combustion air wheel. Once the control board sends power to the motor, it will start operating which will move the shaft attached to both wheels. The movement of both wheels will cause air flow.
Replacement motor for Dometic furnace
Power: 12V DC
Body Dimensions: 3" Diameter x 3" Length
Shaft #1 Dimensions: 1" Long x 5/16" Diameter
Shaft #2 Dimensions: 1" Long x 5/16" Diameter