How to Replace a Blower Motor Resistor

How to Replace a Blower Motor Resistor: A Short Guide for Beginners

The blower motor resistor is an important component of the heating and cooling system of your car. As you turn on the heater or the AC, the fan starts and air will start to get out of the vents. This fan will run because of the blower motor resistor. Therefore, when the latter is damaged, expect that you will experience discomfort in your car.

It is inevitable that this part will experience a serious problem and will ask for a replacement. If you do not know how to do this, keep on reading the rest of this post and we will let you know how to replace a blower motor resistor. You will realize that it is actually an easy task that can be accomplished even without being a trained mechanic.

What You Will Need to Follow this Tutorial

First, gather the tools and materials that will be needed for the replacement of the blower motor resistor, which will include the following:

  • Ratchet
  • New blower motor resistor
  • Wire stripper
  • Electrical tape
  • Dielectric grease
  • Connectors
  • Screwdriver
  • Wire cutter

Step-by-Step Guide on How to Replace a Blower Motor Resistor

Here are the simple steps that you have to follow for the easy replacement of a blower motor resistor:

Replace a Blower Motor Resistor


1. Locate the Blower Motor Resistor

Obviously, the first thing that you have to do is to determine the location of the blower motor resistor so that you know which component will be removed. It is located right next to the blower motor. The latter, on the other hand, can be commonly found underneath the dash on the passenger side or in the engine compartment.

2. Take out the Blower Motor Resistor

Now that you know the location of the blower motor resistor, remove it. You will need to first remove the components around the blower motor resistor, which include the pigtail connected to the AC and the blower motor cooling duct. At this point, you can now have easy access to the blower motor resistor.

Now, all that you have to do is to unscrew the bolts that secure the blower motor resistor in place. Use a ratchet with a short extension. Once the bolts are out, all that you have to do is to pull the blower motor resistor.

3. Disconnect the Wires

After pulling the blower motor resistor, you have to cut off the wires that are connected to the component. Cut the wires using the stripper or scissors that are made specifically to cut through wires.

4. Install the New Blower Resistor

Before you proceed with the installation, apply dielectric grease to the housing of the blower motor resistor. This will prevent water from getting inside, which is a common problem when you are off-road driving. Apply coating around the plastic, which will provide a sort of sealing to protect the component.

Place the blower motor resistor on the exact same place where it has been earlier removed. Use new screws to have it secured in its position. Connect the pigtail and at this point you are done with the job. However, there are also some instances wherein the pigtail has already worn out. If this is the case, proceed to the next step.

5. Wire the Pigtail

Cut down the old wires and connect the new ones. This should be easy as the wires are probably color-coded. Use the connectors to connect the new wires. Put the pigtail in its original position, and at this point you are already done with the task.

To make the steps mentioned above clearer, refer to the short video that is shown below:

Pro Tips

Aside from knowing the steps that are involved, you also need to keep in mind the tips that will be briefly mentioned in this section.

Knowing If It is Bad

How would you know if the blower motor resistor is asking for a replacement? This is not one thing that can be answered with a simple guesswork. There are signs and symptoms that you should watch out for, including the following:

  • One of the most common signs of failure would be when the blower motor is stuck on a single speed. Because of this, the heater or the fan in the car will only function in a single setting and you will notice that the temperature does not change regardless of the adjustments that you make.
  • There is also a problem if the blower motor does not work in specific settings. This can be frustrating as you might be stuck in the same setting.
  • If there is no air coming out from the vent, this can also be one of the indications that the blower motor resistor has already failed. If the blower is turned on but it does not generate any air, check the blower motor resistor.
  • Another easy way to tell the problem with a blower motor resistor would be through performing a quick visual inspection. If there are signs of wear, such as corrosion and rust, it would mean that you will need to replace it.

Tips for Replacing a Blower Motor Resistor

  • You need to remove the components from the blower so that you can easily access the blower motor resistor. This will give you a clear sight of what needs to be removed.
  • The steps mentioned above will be applicable to the removal of the blower motor resistor that can be seen in the engine compartment. If it is in the passenger seat, you will need to remove the glovebox first so that you can remove the component.
  • You might also want to test the resistor first with the use of a multimeter. By doing this, you can be sure that there is indeed a problem with such part and that it is requiring a replacement.
  • The steps mentioned above have also noted crimping the pigtail as a necessary step when the wires are already worn. In some instances, the task might also require the need for shrink wrapping and soldering. They might require more effort, but it will be good in terms of making sure that it will no longer be as easily prone to wear and tear.


From the steps and tips mentioned above on how to replace a blower motor resistor, it is apparent that the task is pretty much straightforward. You will need basic tools to complete the task. There is no need for extensive technical knowledge or a lot of time and effort to spare. You do not have to call a trained mechanic to do the removal and replacement for you.