What is the Blower Motor Resistor and how does it affect your vehicle?

The blower motor resistor is a very important part of the heating and cooling system in your vehicle.  It is responsible for blowing heat or air on the lowest and middle settings of your vehicle and if you hear the fan running on high continually, then you’ll want to get it fixed as soon as possible.

There are two distinct types of blower motor resistors and before replacing yours, you’ll want to ensure that you know which type is installed in your vehicle.  The first is a wire type resistor that uses different size wire coils for each of the different fan speeds, each having their own resistance level while the second is a printed circuit board with a fully integreated electronic circuit.

The typical fix includes replacing the blower motor resistor with a new one which is very easily achieved and also won’t cost a lot of money.

How does it function?

The air that is blown through the motor is controlled by the resistor.  The amount of air that flows through the vents can be altered by the resistor depending on the requirements of the motor.  The lowest setting offers the most resistance to the air flow, while the highest setting offers the none and that is why it is a clear sign that your resistor has blown as there is no resistance being exerted.  It is best not to run your motor continually on the lowest setting as this can esily burn out your resistor again.