What is the difference between a blower motor and a blower motor resistor?

What is the difference between a blower motor and a blower motor resistor?

The motor that runs the fan in the heating and air conditioning system in a car is called a blower motor. A blower motor resistor is a simple electric resistor. It’s used in cars where the blower motor has only 4 or 5 fixed speeds, as on the left side in this diagram. See the photo of a Ford blower motor resistor.

How does a blower motor resistor control the fan speed?

The blower motor resistor controls the fan speed of the blower motor and the resulting change in air pressure produced by the movement of the blower fan. It accomplishes this by regulating the electric current that powers the motor.

What happens when a blower resistor is faulty?

When a blower resistor is faulty, the fan will usually operate at one speed only, usually the highest speed setting possible. Sometimes, only some of the speed settings will be faulty while others might work. When trying to diagnose a blower fan motor, the following steps should be followed:

How much does it cost to replace a blower motor resistor?

The blower motor resistor or control module replacement is not very expensive. For example, one of our colleagues had a problem with his 2011 Ford Escape: the fan only worked at the speed 4. He paid $50 to diagnose and $112 to replace the resistor at a local Ford dealership.

How to test a blower motor resistor in the garage?

Look for obvious signs of corrosion and burns from overheating. If you want to do a quick test of the blower resistor, you can check the resistance of each of the resistors with a multimeter as follows: set the tool to read ohms (a measurement of resistance) and connect one of its probes to the common output terminal of the resistor.

What is the purpose of a blower motor resistor?

The blower motor resistor is an electrical component that is a part of the vehicle’s heating and air conditioning system. It is responsible for controlling the blower motor’s fan speed. A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system.

Where exactly is the blower motor resistor?

Usually it’s located in the dashboard on the opposite side of the steering wheel. You can’t see it because it’s inside the vehicle, but that’s where it is located. The blower motor resistor is the part of the blower motor that controls the speed.

Is there a way to test a blower motor?

Blower Motor Resistor Testing Place one lead of the Ohmmeter on terminal 1 of the resistor. Place the other lead on terminal 2 and check against specifications. Move the lead from terminal 2 to terminal 3 and check this reading against specifications. Move the lead from terminal 3 to terminal 4 and check this reading against specifications.

Why does blower motor resistor keep going out?

The blower motor appears to be defective here. When the brushes wear out the motor draws excessive amps which could cause the resistor to burn out. Before making further replacements remove the motor and check it, especially the brush assembly. This is the most likely reason for the resistor to fail repetitively.