HVAC air direction motor control (face/feet/defrost motor) diagnostic | FerrariChat
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HVAC air direction motor control (face/feet/defrost motor) diagnostic

Discussion in '348/355' started by brendon0, Sep 19, 2018.

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  1. brendon0

    brendon0 Formula Junior

    Dec 13, 2003
    611
    Tampa FL
    Full Name:
    Brendon
    #1 brendon0, Sep 19, 2018
    Ok,

    Cars battery went dead and sat in the rain for a few months. Now this motor wont turn the tumbler
    under the dash to change the air direction.

    I have pulled the motor and want to see if its the motor or ECU that the issue. The motor has a 5
    position connector. I am assuming if I apply 12v to two of these it will turn. Also assuming the other
    3 connectors are are ohm resistance readings so the ECU can figure out where the tumbler is.

    Anyone have any clue what two connectors will take the voltage?

    Also should I be apply 5volts maybe? I know the ECU uses OP-AMPS to drive these things.

    FYI - the motor arm that goes into the tumbler is locked solid, I cant turn it.


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  2. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,566
    San Carlos, CA
    Full Name:
    Mitchell Le
    #2 yelcab, Sep 19, 2018
    Put it back. Turn the battery off and on again and do the rain dance. It will work again. It just needed to be reset and nobody really knows what sequence of events will reset it, but it will reset.
     
  3. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    3,227
    Serbia - Niš
    Full Name:
    Miroljub Stojanovic
    #3 m.stojanovic, Sep 20, 2018
    When looking at the connector as shown on the picture above, the pinout is as shown on the diagram. The red and black wires are to the motor (12V) and the polarity on them is switched over for the flap up or down movements (the motor turning clockwise or anticlockwise).

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  4. brendon0

    brendon0 Formula Junior

    Dec 13, 2003
    611
    Tampa FL
    Full Name:
    Brendon
    #4 brendon0, Sep 20, 2018
    I tired this already, shutting off power overnight and then doing a relearn with A/C disabled.

    Is there specific settings the A/C control panel needs to be on while the 10 minute relearn is running?
     
  5. brendon0

    brendon0 Formula Junior

    Dec 13, 2003
    611
    Tampa FL
    Full Name:
    Brendon
    #5 brendon0, Sep 20, 2018
    Thanks for this - I will try power it tonight with my powerprobe and see if I can get it to turn.
     
  6. redwedge

    redwedge Formula Junior

    Sep 30, 2012
    463
    London
    Full Name:
    Steve C
    #6 redwedge, Sep 20, 2018
    I got mine to reset by unplugging and reconnecting the HVAC ECU under the front carpet. No amount of battery disconnects worked.
     

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