The device that is used to expel air out of the vehicle is known as a blower motor. It does so in two steps. First, the air is blown out through cabin air filter and then through heater core. Direction of the blown air is further controlled by the air control doors. This helps in either cooling or warming the car’s interior. Its functions include defogging the windshield too. If your current blower motor has started troubling you by making a lot of noise on being turned up, then it is the time to have it replaced. You can buy a used blower motor. It would be worth to your every single penny paid.