The blower motor is the fan that pushes heated or cooled air through dashboard vents based on the climate system settings and the fan speed selected. Adjusting the fan speed sends a signal through a resistor to the blower motor to either pick up the pace or slow it down. The blower motor resistor adjusts the amount of current going to the blower motor based on the selected fan speed. When a blower motor fails, only a small amount of air will come through the interior vents based on the amount of outside air entering the climate system. If the fan doesn’t work, before pointing the finger at the blower motor, check fuses for the motor to make sure they’re still good. Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side. Blower motors that make loud squeaks or rattling noises may be worn out and on the verge of packing it in, but sometimes those noises are caused by leaves or other debris that can be cleaned out after the motor is removed from the vehicle.