5 Interesting Questions About Blower Motor Resistor: Here are the answers!

Most of us own a car or an SUV or some kind of the vehicle or other. And most of us are knowledgeable about most of our vehicle’s parts and working. But how many of you know about the blower motor resistor and what it is used for?

To be responsible and self-sufficient car owner, you have to know about all the mechanism and devices in your car and how to take proper care of them. Here we are going to talk about a device that is rarely talked about by common people. We will be discussing the working of the blower motor resistor, its applications and how to check if it is functioning properly.



What Are Blower Motor And A Blower Motor Resistor?

A blower motor is a motor that runs the fan of the engine. It works by controlling the fan speed in the vehicle’s heating and cooling system. The resistor allows the motor to control the speed of the fan on speed settings.

Most of the cars come with just one blower motor resistor, and it is connected to the blower motor, usually inside the air duct. Bigger and more advanced vehicles like SUVs etc., which have separate cooling and heating system for the rear and front seats, may have two resistors. In such cases, the second one might be fixed on the rear seat’s AC or heating system.

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The blower motor resistor is made of 3 or 4 small resistors that are attached to a PCB or in the form of a coiled wire. They do not get damaged easily and do not require maintenance. The resistors need to be replaced in case of any malfunction. Also, they are generally covered under the car’s 3-year maintenance scheme.


What Causes The Blower Motor Resistor To Fail?

There are a couple of factors that can cause your resistor to fail. Since the blower motor resistor is installed inside the air duct of the AC or heater, the continuous flow of air keeps the resistor cool and prevents from overheating. But this varying change in humidity and temperature over time can lead to the failure of blower motor resistor. It can cause the system to corrode and stop working.

Similarly, another reason that may lead to the resistor to malfunction is the possibility of any damage to the blower motor. This can either be a manufacturing defect with the blower motor or some foreign object jamming the blade. The damage causes the device to put out too much power. The damage also causes it to overheat and malfunction, too.


How Do I Know If My Resistor Is Working Or Not?

Now that we have discussed what causes the blower motor resistor to fail, let us see what the symptoms of a damaged one are.

If the blower motor resistor in your car or SUV is malfunctioning, you can easily find it out. In case it is damaged, your car’s air conditioning system or fan will be working without any problem on the higher speeds. However, it will not work in the lower speed setting.

This is because the higher speed directly bypasses the blower motor resistor. In a few cars, it can cause the fan to not work in both high and low speed setting. If you are suffering from such a problem, it might be time to change your blower motor resistor.

Before we replace our resistor, we can make sure that it is actually damaged and is not just a false diagnosis. The exact blower motor resistor testing procedure is different for different vehicles. So it is highly recommended to learn it from the instruction manual.

  • Basically, you have to find the resistance between certain terminals of the resistor and have to compare it with the standard given in the instruction manual. For example, in the blower motor resistor that I tested, the multimeter gave me the value of 1.9 megaohms whereas the standard set by the manufacturer of the vehicle is 1 ohm. This means that the resistor of the vehicle requires replacing.
  • You can also check for any visible corrosion spots or damages that might have caused the blower motor resistor to stop working.


Where Is The Resistor Placed In Your Car?

To replace the blower motor resistor, you need to find about its placement firstly. In some cars like the Mazda Tribute and the Ford Escape that were introduced before 2012, it can be found near the glove box on top of the HVAC.

In the case of cars like the 2001 Toyota Camry, it's attached near the blower motor that near the passenger’s seat. It is cheap and readily available and you can get it replaced in less than 15 minutes. In case you are not experienced enough or cannot find the location of the blower motor resistor, you can ask your mechanic or repair person who will do the replacement for you for a nominal rate.

Depending on the company and the model of your car, the price of the resistor and the ease of its installation changes. A blower motor resistor can cost from 65 dollars to 350 dollars. Most of them can be easily brought from hardware shops or online market. You could easily replace them without any help.


How To Replace The Blower Motor Resistor?

Take care while replacing the blower motor resistor. Wear latex gloves and protective eyewear when working with your vehicle.

Now, let us move on to the actual process of replacing the faulty resistor with a new one.

  • Remove the negative terminal of the battery
  • Locate the blower motor resistor follow the tutorial above
  • Disconnect the electric connectors that go to the resistor
  • Remove the blower motor resistor by removing all the screws and bolts that keep it in place
  • Installing the resistor is the reverse process of removing it. Make sure all connections are secure and proper to avoid other issues


We spend a lot of our time in our cars and vehicles. So, it is important that our cars are fully functional and free of any issues. The heating and air conditioning system of our vehicles are really important. They're necessary for a comfortable and pleasant ride.

The blower motor resistor plays a big role in controlling the temperature and energy flow to the blower motor which in turn controls the heating or cooling of the air conditioning system. So, it is important that we become capable of recognizing the symptoms of a faulty one.

And also learning to replace the blower motor resistor can help us save a lot of money and time that we would have to spend on the mechanic. This is the first step becoming a responsible car owner and also in becoming self-sufficient. Proper care and safety precautions have to be taken while working with your car and tools.

I hope that this article has helped you to understand the importance, functioning and probable failures associated with the blower motor resistor. If you guys have any more doubts or query, feel free to contact us through our comments. Also, share the article so that more people can benefit from the knowledge.

Abigail Jones

Hi, I'm Abigail. I like spending time tearing my house apart and putting it together back again. Join me on home improvement tutorials, tips on my blog.

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