1. Attachments are working again! Check out this thread for more details and to report any other bugs.

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

    Joined:
    Apr 4, 2024
    9
    2
    0
    Location:
    London, UK
    Vehicle:
    2011 Prius
    Model:
    Three
    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
    My Tools: MiniVCI J2534, ELM 327.
    My Apps: TechStream, Carista, Dr Prius
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,133
    50,050
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    is it cold air? the hybrid battery powers the a/c, but the 12 volt powers the blower fan
     
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    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).
     
    seaglasspearl2013 and Brian1954 like this.
  4. fiz

    fiz New Member

    Joined:
    Apr 4, 2024
    9
    2
    0
    Location:
    London, UK
    Vehicle:
    2011 Prius
    Model:
    Three
    Yes, I have solar panel and sunroof.

    Can I switch off this feature permanently?
     
  5. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    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.
     
    seaglasspearl2013 likes this.
  6. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Is that fan run by solar energy, from the solar roof?
     
  7. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
  8. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Ah, subliminally leading the witness again.
     
    seaglasspearl2013 likes this.
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    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

    Joined:
    Apr 4, 2024
    9
    2
    0
    Location:
    London, UK
    Vehicle:
    2011 Prius
    Model:
    Three
    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
    seaglasspearl2013 likes this.
  11. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    45,024
    16,242
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    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.
     
    seaglasspearl2013 likes this.
  12. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,906
    16,213
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    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.