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Aircon blows air when car off

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by fiz, Apr 30, 2024.

  1. fiz

    fiz New Member

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    While my car is completely switched off, its aircon is blowing air possibly.
    I am not sure why, is it due to warm weather (15 degree centigrade)?

    How to switch this feature off as I do not use the car battery heavily?

    Prius 3rd gen 2011 TSpirit UK model
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  2. bisco

    bisco cookie crumbler

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    is it cold air? the hybrid battery powers the a/c, but the 12 volt powers the blower fan
     
  3. ChapmanF

    ChapmanF Senior Member

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    Is there a solar panel on the roof of the car?

    If so, that is a feature. There is a switch on the dash to turn it off. It's near the panel-light dimmer (or at least on US models that's where it is).
     
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  4. fiz

    fiz New Member

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    Yes, I have solar panel and sunroof.

    Can I switch off this feature permanently?
     
  5. ChapmanF

    ChapmanF Senior Member

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    When you switch it off, that's permanent unless you switch it on again.

    Of course, the feature is there to prevent the buildup of heat in the cabin in hot weather, requiring extra cooling when you start the car, both for your own comfort and for the health of the battery. So maybe it would be worth weighing what the feature does against what it costs you.
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Is that fan run by solar energy, from the solar roof?
     
  7. ChapmanF

    ChapmanF Senior Member

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  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Ah, subliminally leading the witness again.
     
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  9. ChapmanF

    ChapmanF Senior Member

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    Also, in the cars with that feature, they replace the conventional brush-commutated blower motor and use an electronically-commutated one with no brushes to wear out, so the extra hours of blower runtime won't be a big deal.
     
  10. fiz

    fiz New Member

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    Does the solar panel also charge the hybrid battery?

    I was worried that the battery would deplete from the fan running continuously.
     
    #10 fiz, May 1, 2024
    Last edited by a moderator: May 1, 2024
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  11. Tideland Prius

    Tideland Prius Moderator of the North
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    The solar panel does not charge the hybrid battery. It has its own small battery.

    The only battery it'll deplete is its own and it's entirely separate from the operations of the car. The 12V does not run.

    The solar panel will run continuously or intermittently depending on the available solar energy.

    The button to toggle the "Solar Panel Ventilation System" is on the right of the steering wheel amongst the button for headlight washers (if equipped) and the dial for the rheostat.
     
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  12. ChapmanF

    ChapmanF Senior Member

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    I'm not aware of the gen 3 solar vent having any battery at all.

    As Tideland explained, nothing that happens is draining either battery in the car. The blower power when the car is off is coming from the solar panel.

    In enough sun for the blower to run continuously, it will. In less sun, it will run in bursts. I would guess the solar vent ECU accomplishes that with a capacitor, rather than a tiny battery (though I haven't taken that ECU apart).

    I (and various others) have modded the system so the panel can also help keep the 12 V battery charged. Since doing it myself, I've been able to leave the car parked unused as long as I want and never worry about coming back to a flat 12 V. And on even moderately sunny days the panel still runs the vent too.