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Engine cooling fan not working, pls help!

Discussion in 'Prius v Technical Discussion' started by MM.87, Aug 19, 2024 at 11:03 PM.

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  1. MM.87

    MM.87 Junior Member

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    Hi.

    I have a 2013 V w/ 337k miles.

    Engine cooling fan stopped working a few weeks ago. AC is not cold unless the car is moving 30MPH+ and if it is a hot day with a lot of stop and go traffic the high temp indicator will come on, so I stopped turning the AC on since last week. Coolant is boiling/gurgling but no coolant loss. No DTC codes. Fan relays 1, 2, and 3 were tested and they are all fine. A Bi-directional scanner couldn’t turn the fans on. The cooling fans used to be on and on mid-high speed all the time w/ or wo/ AC on. I’m still using the car daily. Please share your experience. Thank you!
     
    #1 MM.87, Aug 19, 2024 at 11:03 PM
  2. MAX2

    MAX2 Junior Member

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    #2 MAX2, Aug 20, 2024 at 12:53 AM
  3. rjparker

    rjparker Tu Humilde Sirviente

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    Low speed has both fans in series while high speed has full power to both. Check the power and grounds at the fans with the scanner activating them (car in On rather than Ready) to avoid overheating.

    Since both fans are out based on your testing, I might suspect the grounds.

    Low speed
    Prius gen3 Cooling Fans.jpeg

    High speed
    IMG_6034.jpeg
     
    #3 rjparker, Aug 20, 2024 at 10:40 AM
    Last edited: Aug 20, 2024 at 5:58 PM
    MAX2 and Air_Boss like this.
  4. MAX2

    MAX2 Junior Member

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    Or fuses for supplying 12V to the fans
     
    #4 MAX2, Aug 20, 2024 at 10:19 PM
  5. BiomedO1

    BiomedO1 Senior Member

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    I wouldn't be driving that around in rush hour traffic. That's a good way to break something, ie. pop the head gasket or warp the head.

    Check the fuse, then the relays. Swap with another known good relay in your fuse box (ie. headlamp relay). Turn on your headlight, swap fan relay with headlight relay - is the headlights still on? That's how you check relay operations.
    If you can disconnect the fan from the wiring harness, you can use jumper wires to hook the fan directly to a battery. That'll determine if you got bad fan motors or wiring and control circuit issues.

    Hope this helps...
     
    #5 BiomedO1, Aug 20, 2024 at 10:45 PM
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