Blower Not Blowing

Discussion in 'Gen 3 Prius Technical Discussion' started by andmason311, Feb 11, 2025.

  1. andmason311

    andmason311 New Member

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    My story begins about a month ago when I routinely started up my incorrigible Pria (Prius Name). To my slight discomfort, my AC was not turning on, even though the dashboard buttons and screen seemed to indicate it was. This required me to whip down the inside windshield of condensation throughout the day. From my slight research I squeezed in between tasks, I figured it was either a sensor, blower, or filter issue. I began by removing my lower glove box compartment on the passenger's side, removing the filter, cleaning the filter, replacing it, and starting up the car. To my splendor, this fixed the blower issue. I then gleefully drove around with working AC and Heat over the next month.

    Fast forwarding to 2 days ago, I ran into the same issue after car camping on a chilly night. When I woke up and tried to warm my hands, I again discovered that my blower was not blowing air through the vents. I tried both hot and cold settings but still nothing came out. I tried the ol' filter replacement trick as I had done before and nothing. I tried it several times in varying configurations and steps, but still, no air was being blown through the vents. I again drove a full day without AC or heat. The next day driving to work, however, I went over a speed bump and immediately after the josel, the car heat kicked back on. I am a little bamboozled by this experience and would love to hear people's opinions as to the issue plaguing Pria.

    Patterns of note that I have not ruled out: The issue lasted about a day each time, the temperatures on both days were in the low-mid 40s, and the blower was initially set to hot when the failure to blow air occurred after startup. I am unsure if it is a loose wire sensor, a temperature-dependent blower issue, a bad blower, or some other manner of magical curse but on me. Thanks for all the help and discussion below. I know it's not the most pressing or shocking issue, so I appreciate you all reading through my post.
     
  2. Brian1954

    Brian1954 Senior Member

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    How were you controlling the heat and AC, in auto mode or in manual mode.
     
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  3. ASRDogman

    ASRDogman Senior Member

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    It could be the brushes are worn, and/or dirty. Smacking it, or a bump moves the fan enough
    to get contact and the blower starts to turn.
    There is also a possibility of a loose connector or damages wire, by a rodent?
    Disconnecting and inspecting each connector, cleaning if needed, and reinstalling each one
    could help.

    Annnddd…. it could be a sensor. The best thing to do, after trying the above things, would
    be to use a diagnostic tool and rule out things…..

     
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  4. ChapmanF

    ChapmanF Senior Member

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    Gen 3 came with and without a "solar roof option". At least early ones did; maybe I don't know if that was still a thing for 2015.

    Anyway, I mention it because the solar-roof models came with a brushless version of the blower motor, unlike the non-solar ones with conventional blower motors that can do stuff like this when the brushes wear.

    The motors interchange, so if you find a salvage one from a gen 3 solar-roof Prius, you can spend all your time gleeful instead of bamboozled.

    (Of course, if you have a solar roof model, then your problem isn't motor brushes. Just fergit I said anything.)
     
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  5. andmason311

    andmason311 New Member

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    The blower was in manual mode. Although I believe I did try Auto and had no immediate success.
     
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  6. andmason311

    andmason311 New Member

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    This was helpful information. My model does not have a sunroof so I will be trying to search for a brushless blower motor on ebay and my local pick-your-parts place. Very helpful information. I will be trying to clean my motor first and see if the problem persists.
     
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  7. ASRDogman

    ASRDogman Senior Member

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    If you remove the motor, you can see where the brushes are and the commuter.
    If it’s dirty, that could be your problem. Likely the brushes are worn down, so cleaning
    might help, for a while.

     
  8. ChapmanF

    ChapmanF Senior Member

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    Between the brushes you will see the commutator. The commuter is what it sees if it looks back at you.

    Funny thing about commutators: I had a car whose blower motor would occasionally blow its own fuse and stop working. The brushes had been wearing long enough that there was fine conductive carbon brush dust packed into the little gaps between the commutator segments. Sometimes the motor would come to a stop positioned just right with nothing but carbon-packed gaps lined up from one brush to the other. Next time you turned the blower on, poof!

    But enough juice would still flow through the windings to kick the rotor around a few degrees, so the same thing wouldn't happen again the next time. Just some random time again after that.

    Worked better after cleaning up the commutator, using I don't remember what, maybe a toothpick was hard enough without being too hard, scraping all the packed carbon dust out of all the gaps between segments.
     
  9. bbrages

    bbrages Member

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    I had a noisy blower motor, and I replaced it with the brushless one from a junkyard pick. Works well. I don't remember the old one being something you could service, though.

    My son had intermittent operation on his 2nd gen. We put in a Rockauto blower and that fixed it.
     
  10. andmason311

    andmason311 New Member

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    Ive taken apart the blower motor as much as I can but still cant get the scroll wheel cage off. Any suggestions to getting access to the brushes for cleaning? I am able to get some carbon dust or black dust out by tapping it.
     

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  11. ASRDogman

    ASRDogman Senior Member

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    At the center of the fan, how is it attached? Is there a clip? The photo isn’t good enough
    to be able to tell…. There might be a clip you pop out. USE A MAGNET so it doesn’t fly away.
    Then the fan should pull off. It will likely be snug.