1999 Chevrolet Lumina - Blower Motor Resistor

Learn How To Replace A Blower Motor Resistor

A blower motor resistor controls the speed of the blower motor and is crucial to provide air flow in your vehicle's cabin. When you turn on or adjust your heating or cooling system and fan speed, the blower motor resistor adjusts the amount of electrical resistance to control the power sent to your blower motor. This allows your car's blower motor resistor to control fan speed, and these settings can be adjusted either manually or automatically in some vehicles. While they're designed for a long life, a blower motor resistor can wear out and fail due to time, constant use, and excessive heat. Signs that you may need to replace your blower motor resistor include a decline in heating and A/C system performance, the blower motor only working on the highest setting or becoming stuck on one speed, erratic fan speeds, or if there is no air coming from the vents. These symptoms may also point to a blown fuse or damaged relay, a worn blower motor, or a clogged cabin air filter, so it's important to perform a complete diagnosis before replacing the blower motor resistor. Failed blower motor resistors also often appear burned or melted, which can be helpful when determining if your blower motor resistor needs to be replaced. While a bad blower motor resistor will not affect your vehicle's performance, it can impact the comfort and enjoyability of your car, and a non-working defrost system can even affect your safety. If you're only noticing issues with hot or cold air, you can learn more about why your car's heater is failing and why the AC in your car isn't working to help you better identify the source of the issue. Learn even more about your car and how to perform DIY car air conditioning repairs with our How-To Hub You'll find topics like how to replace a blower motor resistor and much more. When you're ready to make your repair, you can find a new blower motor resistor, blower motor, cabin air filter, and much more at O'Reilly Auto Parts.