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Prius Radiator Fans direction?!

Discussion in 'Gen 3 Prius Technical Discussion' started by PittsburghPrius, Aug 1, 2019.

  1. ASRDogman

    ASRDogman Senior Member

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    I think the connectors are different. Because one is for a single fan for just the engine-radiator.
    And the other one is for the a/c. But usually when you click the compressor kicks in both fans run.
    But you could check the voltage at the plug and ground and see which one is the 12v.
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Same scenario, I count 7 on the right. I put a Sharpie marker dot on one blade, then counted till it came round again.

    Not enough room to count left fan, but would assume its 9.

    So the opposite of what you're seeing.

    Just to clarify, I'm looking at them like this, fan on right (with dot) is seven blade:

    upload_2019-8-14_17-53-3.png
     
    #22 Mendel Leisk, Aug 14, 2019
    Last edited: Aug 14, 2019
  3. PittsburghPrius

    PittsburghPrius Junior Member

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    Thank you for checking! I did the same thing with a sharpie to count mine. Will attempt fan swap next week.
     
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  4. ChapmanF

    ChapmanF Senior Member

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    There is an age-old sacred tradition, though, that the words 'left' and 'right' in automotive work always mean when you're facing the same way the car is.

    That fan looks like the one on the left, even if it's on your right when you're standing in front looking back.
     
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  5. ASRDogman

    ASRDogman Senior Member

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    The standard is the direction is when one is sitting in the DRIVERS seat.
    Even in England. :)
     
  6. CR94

    CR94 Senior Member

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    Right! The left side of a car (or person, for that matter) is always the left side, no matter where the observer is located.
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    I was speaking the same language as OP, he was viewing that direction, described them thus, and I quoted him.
     
  8. ChapmanF

    ChapmanF Senior Member

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    Even so, as sometimes an OP will not be aware there's an existing convention for left/right, it can be worth mentioning that, to head off future confusion when reading the manual, etc.
     
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  9. ChapmanF

    ChapmanF Senior Member

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    Little followup to make sure later readers have this.

    The two motors spin opposite directions. The directions are blade-top-toward-car-midline for both. Thinking of it that way avoids the questions of which-way-are-you-facing and such.

    The two blades have opposite pitch, and need to be installed so that blade-top-toward-car-midline makes both of them pull air through the radiators and into the engine compartment.

    They also have different blade counts for some reason (maybe just to make them easier to tell apart?), and the one with more blades is the one that is lower and on the right side of the car.

    [​IMG]

    I would love to hear somebody say there's a way to replace these without draining and removing the whole radiator.
     
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  10. tony_2018

    tony_2018 Member

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    The fan moves in a way that pulls air from the outside in. It moves to pull cooler air through your condenser and both radiators. It does not push engine bay hot air through it.
     
  11. ChapmanF

    ChapmanF Senior Member

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    What seems to trip people up most often is the fact that there are two fans, and the motors spin opposite directions, so the two blades are made with opposite pitch, so that both of them pull into the engine bay when rotating in their respective directions.

    If somebody reassembles with the blades swapped, they will both end up pushing. Or if somebody replaces one fan motor or blade with the wrong one, the result is a push-me-pull-you.

    Hence post #29 to clear up which way things go.
     
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  12. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I keep thinking this is sand-pounding conflation. It doesn't matter a hill-of-beans which direction the fans spin, only which direction they move the air, and they both should be pulling air into the engine bay. And they very likely are, lol.
     
  13. ChapmanF

    ChapmanF Senior Member

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    Thing is, I believe I've seen posts where the car has been put back together wrong, resulting in either: both fans pushing when they should be pulling (which you get if you simply take it apart and reassemble with the blades swapped), or one pushing and one pulling (which you get if you replace one blade or one motor, and either you or the seller mistook which one you needed). And it then mystifies people, if it isn't explained clearly that (1) yes, they should be rotating opposite directions, and (2) yes, the blades have to be matched to the motors so they both end up pulling.

    Philosophically, it doesn't matter a hill-of-beans what directions they rotate, but to avoid mystery cooling problems on reassembly, or to sort them when you discover them, you really kind of do have to know.
     
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, hold a ribbon or something in front of the fan, on the engine side (carefully, you want to keep your fingers), and see which direction it streams.
     
  15. ChapmanF

    ChapmanF Senior Member

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    The fans appear to be a pain in the butt to remove and replace (unless somebody makes my day and posts about a way to do it without draining and removing the whole radiator the way the manual says).

    So probably the last thing you want to do is put it all together and then get a test ribbon sucked into the fan and realize you have to go through all that again to make it right.

    There's the incentive to pay attention to the details the first time.
     
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  16. tony_2018

    tony_2018 Member

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    Best to find a system that can drain it out without collecting dirt and debri and use a some sort of filter to ensure nothing gets in the system.