550 blowing Fuse on AC everytime one is put in. | FerrariChat
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550 blowing Fuse on AC everytime one is put in.

Discussion in 'Technical Q&A' started by Patek, Sep 27, 2012.

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  1. Patek

    Patek Formula 3

    Mar 24, 2006
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    John Milton
    #1 Patek, Sep 27, 2012
    I have my 1998 F550 down at the dealer. Had the A/C rebuilt down there 2 weeks ago.
    Now the fan will not work at all, turn it to 4 nothing, turn it to one nothing, Not even hot air will come out of the vent.
    Took it down on Saturday, blown fuse, put one in blows.
    Talked to them today, they are not sure why it is blowing.
    Anyone have any thoughts that may be the cause.
    It only started blowing the fuse after the Rebuild. Is there a wire somewhere, it was the
    7.5amp that was blowing.
    Thanks,
    John
     
  2. finnerty

    finnerty F1 World Champ

    May 18, 2004
    10,406
    #2 finnerty, Sep 27, 2012
    So, the fuse is blowing when the fans AND the A/C are both on --- or just when only the fans are on?
     
  3. Patek

    Patek Formula 3

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    #3 Patek, Sep 27, 2012
    Even with the AC off it, the fan will blow the fuse I am guessing. No air comes out even with the AC off.
    Strange. Maybe a wire is nicked, or something crazy like a ghost in the machine.
     
  4. vrsurgeon

    vrsurgeon F1 World Champ
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    #4 vrsurgeon, Sep 27, 2012
    It's either in the line TO the blower motor.. or it's the blower motor itself.

    The way I'd test it is to disconnect the blower motor under the dash and then replace the fuse and turn the motor on. If it blows.. it's in the line.

    If fuse doesn't blow with above and then you reconnect the blower motor connection and it then blows again.. motor is bad. Probably a bad brush in the motor.

    #21 on table 57 in ricambi..
     
  5. Patek

    Patek Formula 3

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    #5 Patek, Sep 27, 2012
    Thanks for that info. Now I will sound smart when I quiz the dealership today.
    It always helps to be informed about anything that you are doing these days.
    Even my MRI has been lost in a Doctor's office today. Post office says it has it
    they say they don't. My mercedes has a tow in problem on the back, but you have to
    ask a lot of questions and if you don't know the question to ask, you are backing up.
    Must be Thursday the 13th.
    Everyone I talk to today, Dr's, Mechanics,tire people, I have no answers from any of them.
    May go back to bed, and start again on Monday. Let everyone get sorted out.

    But thanks for telling me.
     
  6. Red Head Seeker

    Red Head Seeker Formula 3
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    #6 Red Head Seeker, Sep 27, 2012
    If the brushes are bad....just spend $10.00 for a new set of brushes....DON'T let the dealer sell you a complete motor....Mark
     
  7. vrsurgeon

    vrsurgeon F1 World Champ
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    #7 vrsurgeon, Sep 27, 2012
    Call the place that did the MRI.. they'll get another out or SHOULD be able to Fax the read to your doc.

    Sillyness. :)
     
  8. stevegtsi

    stevegtsi Formula Junior

    Feb 21, 2004
    316
    #8 stevegtsi, Sep 27, 2012
    the only thing that was done to the a/c system was to rebuild the compressor. if the fuse is blowing i think its a bad clutch winding or a bad diode. i have compressors rebuilt and tested if you need one. send me a pm.
     
  9. Patek

    Patek Formula 3

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    #9 Patek, Sep 27, 2012

    I called again, and they found it on the desk. But it sure did sweat me. My shoulder has been goofed up , I guess from 40 years of playing tennis. Can't imagine a body breaking down in such a short time :)

    Best,
    John
     
  10. PAP 348

    PAP 348 Ten Time F1 World Champ
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    #10 PAP 348, Sep 27, 2012
    How do you know all they did was rebuild the compressor Steve? :D

    If that's all they did, I agree with you.

    But maybe they replaced the evaporator also and rebuilt the fan too.

    My thoughts are they have wire caught/rubbing somewhere that is shorting the blower fan fuse.

    That or they wired up/shorted the blower motor when they rebuilt it.

    Actually, what EXACTLY did they rebuild in your a/c system Patek? :)
     
  11. finnerty

    finnerty F1 World Champ

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    #11 finnerty, Sep 27, 2012
    My thoughts as well.

    First thing I would do is put an Ohm meter between the positive terminal of the fuse socket (with the fuse out) and chassis ground and see if there is any continuity --- if so, you have a ground fault (short) somewhere.
     
  12. Patek

    Patek Formula 3

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    #12 Patek, Sep 27, 2012
    The whole 9 yards, Clutch, Evaporator, Ferrari of Atlanta sent it out to be done, and this place did everything you could do to one.

    Best,
    John
     
  13. Patek

    Patek Formula 3

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    #13 Patek, Sep 27, 2012
    It worked for about a week.
     
  14. RDM

    RDM Karting

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    #14 RDM, Sep 27, 2012
    John, I presume fuse #20, AC control system, is blowing, not #22 AC compressor.i would stay focused on that circuit, not the compressor rebuild or evaporator valve. Best, Doug
     
  15. Patek

    Patek Formula 3

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    #15 Patek, Sep 27, 2012
    I think they said it was the fuse 4th from the left maybe. But, it was the 7.5 amp.
     
  16. Doctor Mark

    Doctor Mark Formula Junior

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    #16 Doctor Mark, Sep 28, 2012
    Let FOA sort it out. They are very competant and honest and while not cheap(then again who is) they will stand by their work 100%. If it is related to something that was done , they will make it right for you.
     
  17. Patek

    Patek Formula 3

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    #17 Patek, Sep 28, 2012
    I am very pleased with FOA for sure. I just have a habit of wanting to trouble shoot everything. I like to know why things happen so I don't do them again if possible :)
     
  18. andyww

    andyww F1 Rookie

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    #18 andyww, Sep 28, 2012
    Hopefully they wont use the method someone I used to work with used to find causes of a blown fuse, ie wire across the fuse and look to see where the smoke came from!
     
  19. Patek

    Patek Formula 3

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    #19 Patek, Sep 28, 2012
    Smoke will get your attention : )
     
  20. It's Ross

    It's Ross Formula 3

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    #20 It's Ross, Sep 28, 2012
    Doubtful this is a bad blower motor or compressor clutch as they would both require a fuse of a higher capacity.
     
  21. Patek

    Patek Formula 3

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    #21 Patek, Sep 28, 2012
    Yeah, it is the 7.5 blowing.
     
  22. finnerty

    finnerty F1 World Champ

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    #22 finnerty, Sep 28, 2012
    Here's also something simple to check.....

    Could it be that something has just jammed up the works --- keeping it from spinning, and drawing too much current as the motor stalls out ?

    If you can access the blower motor without too much trouble, reach in and try to turn the fan by hand ---- see that it is indeed spinning freely, and is not jammed up by anything --- debris, misalignment, etc.
     
  23. PAP 348

    PAP 348 Ten Time F1 World Champ
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    #23 PAP 348, Sep 28, 2012
    Great to hear, did they replace all these parts or rebuild them? :)

    Also curious, did they replace any hoses also? *This has nothing to do with your fuse blowing*
     
  24. Patek

    Patek Formula 3

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    #24 Patek, Sep 28, 2012
    Latest update, Ferrari of Atlanta, sent it out to the air people to see if the clutch is a problem. But, at the moment they don't know.
    I need the car next weekend for 2 car shows, and I am blowing fuses for some unknown reason. Really makes me think a Porsche Twin Turbo would be a breeze as far as mechanical woes. Can't believe I would even think that. BUt everytime I get into a porsche I am just bored to death. And, would just not enjoy seeing it in the garage.
    : (

    But, I am having crazy thoughts, talk me out of it. I have been on Autotrader looking at other cars the past few days.

    Maybe a 959. 1973 Rs, a race 917, glad I don't have the budget for that.
     
  25. finnerty

    finnerty F1 World Champ

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    #25 finnerty, Sep 28, 2012
    Contrary to your recent experience / trouble, the 550 is a wonderful (and quite reliable) car --- don't give up on 'er just yet.... you may regret it ;)
     
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