The A/C fan motor provides the necessary force to rotate the fan inside of the A/C system and blow air into the cabin of the vehicle. The motor is part of the fan unit and comes with a replacement fan.
The A/C fan is typically located within the dash, behind the cabin air filter. Automotive A/C fans require a decent amount of lubrication to ensure a long lifespan. Over time, dirt and corrosion settle into the fan motor and decrease performance until the fan can no longer operate. New replacement fans come with a motor and are sold as a package for the specified vehicle.
If the fan is being serviced by the vehicle owner and not a certified technician, it is advised that the fan be thoroughly inspected before a new unit is inserted. A blown fuse may cause a fan to malfunction. Replacing the fan is not advised at this point. While the vehicle is off, the owner should follow the directions specific to the vehicle being serviced, as stated by the manufacturer, to access the A/C fan unit safely.
Once the fan has been located, the owner should check to see if it spins smoothly. If there is a large amount of resistance, the fan has reached the end of its lifespan and needs to be replaced by a new unit. A smooth spinning fan that does not function is likely the victim of an electrical issue. It should be serviced by a certified automotive technician who can test the voltage being received by the unit and replace a fuse if necessary.