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Speedometer on 348 ts

Discussion in 'Technical Q&A' started by mopacc, Aug 2, 2006.

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  1. mopacc

    mopacc Rookie

    Aug 2, 2006
    7
    #1 mopacc, Aug 2, 2006
    I own a 348 ts 1991. The speedometer ceased to function and I discovered a broken wire on the rev sensor located on the rear left axle. It is a Veglia pn 68.0517.1 sensor. I can solder the wire back on but how do I check the sensor ? If I measure the resistance between the two wires I get 2 Mgohm or more. How does this system work ?
     
  2. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
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    #2 PassionIsFerrari, Aug 2, 2006

    There is one for sale on Ebay...
     
  3. PAP 348

    PAP 348 Ten Time F1 World Champ
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    #3 PAP 348, Aug 2, 2006
    Welcome to Ferrarichat.
    This may help you. :) Courtesy of No Doubt's primer page and fellow members of the brotherhood helping add to it. Thanks also to Miltonian for this speedo info. ;)

    http://webpages.charter.net/aircover/348/1994Ferrari348Spider.html#Speedometer
     
  4. Ricambi America

    Ricambi America F1 World Champ
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    Dec 7, 2003
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    #4 Ricambi America, Aug 2, 2006
    Ask ernie how to remove the sensor....

    bahahahawahaha
     
  5. PAP 348

    PAP 348 Ten Time F1 World Champ
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    #5 PAP 348, Aug 2, 2006

    Or..............you could just solder the broken wire together and then check to see if the speedo works again. Why do you want to check the resistance of the sensor? If you can solder the broken wire, do it and see if it fixes the speedo brother. It should have continuity across the sensor wires. If its ok. Good luck. :)
     
  6. mopacc

    mopacc Rookie

    Aug 2, 2006
    7
    #6 mopacc, Aug 2, 2006
    Actually what happened a mechanic did just that and installed it. It still does not work. He claimed to have measured 6-7 kohm across the wires. I then removed it my self and measured 2 Mohm. Broken or some electronics inside ?
     
  7. mopacc

    mopacc Rookie

    Aug 2, 2006
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    #7 mopacc, Aug 2, 2006
    I cant find that. Where ?
     
  8. ernie

    ernie Two Time F1 World Champ
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    #8 ernie, Aug 2, 2006
    LOL

    Your a baaaad man!
     
  9. PAP 348

    PAP 348 Ten Time F1 World Champ
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    Dec 10, 2005
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    #9 PAP 348, Aug 2, 2006

    Maybe your speedo head is faulty? These are electronic units. Maybe it is not getting power? Time to bust out the test light and multimeter start diagnosing mate. :)
     
  10. mopacc

    mopacc Rookie

    Aug 2, 2006
    7
    #10 mopacc, Aug 2, 2006
    I did that already, and from what I can measure it looks ok. It would be nice to know what signal I should expect from the sender. If at least I could be certain if the problem was at the sender or the receiver.
     
  11. ernie

    ernie Two Time F1 World Champ
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    #11 ernie, Aug 2, 2006
    Just get a new one from Daniel.
     
  12. f355spider

    f355spider F1 World Champ
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    May 29, 2001
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    #12 f355spider, Aug 2, 2006
    I'd agree....they are only $130 or so...and fail every few years or so...if it is not it, you have a spare! ;)
     
  13. ernie

    ernie Two Time F1 World Champ
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    #13 ernie, Aug 2, 2006
    I figured out why.

    When I busted the head off of my old sender, OIL came out of it. Yup, there was oil inside the sender. The problem is that the appoxy that they use to seal the back of the magnet, the end that gets screwed inside the side cover, gets dried out from the heat or just being old. Sort of the same deal that happens with the stupid cats ecu's. Then it separates from the sides of the sender, oil gets inside, and causes problems will all the elecrical stuff inside the sender.
     
  14. PAP 348

    PAP 348 Ten Time F1 World Champ
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    Dec 10, 2005
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    #14 PAP 348, Aug 2, 2006

    I think it is a wave signal you would have from the sender to speedo head. Would need an oscilliscope to see it and you would have to back probe into the sender unit. I could be wrong though. :)
     
  15. f355spider

    f355spider F1 World Champ
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    #15 f355spider, Aug 2, 2006
    Funny I have NEVER replaced a sender for any other car I have owned, but have done so on my 78 308GTS, 1997 355 spider and it was replaced once by the previous owner of my 87 328GTS...Veglia...Italian for "crap"...lol
     
  16. mopacc

    mopacc Rookie

    Aug 2, 2006
    7
    #16 mopacc, Aug 3, 2006
    Thanks for your answer, I think you are right.
    I am going to buy a new one. I have an oscilloscope and will measure the output. Then I will post it on this forum.
     

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