Tips for Changing a Blower Motor

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on December 14th, 2024

Reading Time: 4 minutes
Summary
  • The blower motor forces air through your vehicle’s heating, ventilation, and air conditioning (HVAC) system. When you adjust your vehicle’s A/C, the blower motor speed changes according to your settings.
  • If your vehicle’s blower motor is inoperative, it’s best to hire a professional mechanic to repair it.
  • The mechanic will have the right tools for the job, know how to locate the blower motor, and prepare the vehicle accordingly before disassembly.
  • A good mechanic will take care when removing the blower motor, and they’ll orient the new blower motor based on how the old one was installed. The mechanic will also test the motor afterwards to ensure that the HVAC system is running well.

The blower motor is one component that you might need to replace if the HVAC system isn’t working properly. Let’s take a look at what the blower motor does and some tips for changing it if it wears out.

What Is a Blower Motor?

The blower motor is a 12-volt electric motor fitted with a squirrel cage fan that it spins inside the evaporator housing. It either gets its air from outside the vehicle (NORM A/C) or from inside the vehicle (MAX/Recirc). | Image Source: Richard McCuistian

If the system’s set to cool, the blower motor only blows air through the A/C evaporator, then into the cabin through the registers.

When the A/C is working, the evaporator will dehumidify the air. But even when the A/C isn’t engaged and the system is set to heat, the blower’s air always passes through the evaporator before passing through the heater core. It does this because, on defrost, the A/C compressor will be engaged automatically so the evaporator can dehumidify the air before it ever reaches the windshield.

When you adjust your vehicle’s A/C, the blower motor speed changes according to your settings. On older vehicles, a switch and stepped resistor assembly controls the blower motor speed (see diagram), while in newer vehicles, the blower motor receives instructions from a module connected to the HVAC control unit. | Image Source: Richard McCuistian

If your vehicle’s HVAC system has airflow issues, it’s possible that the blower motor is malfunctioning and needs to be replaced. An inoperative relay or heater controls can also lead to HVAC airflow problems. It’s best to bring your vehicle to a trusted auto repair shop so they can diagnose and repair any HVAC system issues unless you’re a confident DIY person.

Blower Motor Replacement Breakdown and Tips

Locating the Blower Motor

It will either be under the dash on the passenger side or accessible under the hood, but it’s always on the passenger side of the vehicle, never on the driver side.

Vehicle Preparation

Make sure the key is switched to the OFF position (you don’t need to disconnect the battery to do this job). Remove anything that’s in the way; this includes the lower trim panel underneath the glove box. On many vehicles nothing is in the way. The bolts may require a long ¼ inch extension and wiggle socket to get to the harder to reach fasteners holding the blower in place.

Disconnect the blower motor wiring connector, carefully inspecting the terminals for evidence of heat. This is very common on blower motors. In many cases, the blower and/or its resistor will need to be replaced together along with melted connectors. | Image Source: Richard McCuistian

The blower resistor will be near the blower. You may need to look up where it’s located, but always check it for heat damage and melting when you’re replacing the blower motor. Sometimes the resistor is the only problem and the blower motor is just fine.

Always check the blower resistor for heat damage and melting when you’re replacing the blower motor. Sometimes the resistor is the only problem and the blower motor is just fine.

Richard McCuistian, ASE Certified Master Automobile Technician
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Blower Motor Removal

There will likely be three to six bolts holding the motor in place. Afterwards, the entire blower motor assembly can slide out, but it may be tight. That squirrel cage requires quite a bit of space, so be careful while sliding it out of there.

Properly Installing the Replacement Blower Motor

To install the new blower motor, orient it based on how the old blower motor was facing. Check to see if any gaskets need to be replaced.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Some blower motors will have a foam gasket around the flange, and if they do, the new blower motor will usually come with one already in place.

After plugging in the power connections, test the blower through all its speeds. If your vehicle has a cabin air filter, replace it too.

Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician
Tags: blower-motor