How to Replace a Blower Motor

If you have to replace a blower motor in your vehicle it really is a pretty easy job.  Your blower motor is just the fan that moves air through your ventilation system.  It pulls air either from outside your vehicle or in your cabin and then pushes it over your heater core or your AC evaporator to heat or cool the air.  Next it goes through a series of flaps and ducts and comes out the vents you’ve selected.

You may replace your blower motor for a few different reasons:

Reasons to Replace a Blower Motor

• Poor airflow from your vents
• No airflow from your vents
• A noisy fan

In the video above we had poor airflow from the vents in our GMC Sierra.  You can see how about half of the fan blades were covered so the fan wasn’t moving much air.  Even on high when it made a lot of noise we weren’t getting the power we wanted.  If you’re replacing your blower motor for this reason, make sure you do like we did and clean everything out as best you can.  This can include changing the cabin air filter and vacuuming everything out before installing your new blower.  If you can it’s best to get eyes on your heater core to make sure there isn’t a bunch of junk blocking air flow through it as well.

If you don’t have any airflow from your vents it could be that you’ve got a bad blower motor or could be that you’ve got another problem with your HVAC system.  The best thing to do is to pull the plug out of the blower motor and check to see if you’re getting voltage across it.  Your system varies fan speed by changing the voltage so depending on what speed you have the fan on you might see less than 12 volts.  If you don’t see any voltage it’s time to check other components like the blower motor resister we pointed out.

Noisy fans can often mean it’s time for a new blower motor.  Like any spinning machine, your blower motor has bearings to keep things spinning quietly and these bearings do wear out.  This is especially true if your fan is imbalanced like ours was.

Blower motors are a pretty easy job because they often can be pulled down into your passenger’s footwell.  Before you pick up a new blower motor do a little research because on some cars it can take a lot to replace a blower motor.  This can include removing your whole ventilation unit or the entire dashboard.

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Photo by Olav Tvedt on Unsplash