As mentioned earlier, the fan motor is one of the most difficult parts to operate in an air conditioner. Wear and tear eventually takes its toll. However, regular HVAC maintenance can prevent fan motors from burning out sooner than expected.
It's a good idea to check your AC fan motor every year or at least every two years. This will help make sure it's working properly and you don't miss any signs of a problem.
If the AC fan motor is only working intermittently, you may notice a humming sound inside the AC unit upon startup. This is due to poor electrical connection resulting in poor contact with the motor power supply.
Your air conditioner is useless without a functioning fan or furnace blower motor. It could also mean you need to service your furnace, or should start thinking about the cost of replacing the blower motor.