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348 speedo trouble

Discussion in '348/355' started by 95spiderman, Sep 29, 2005.

  1. 95spiderman

    95spiderman F1 Veteran
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    Nov 1, 2003
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    help.
    my 95 spider speedo/odo has been intermittent lately. i was told here in old thread to check 'sending unit' which is located between drivers shock tower and charcoal canister. i thought i found it but turned out to be a clutch connection. there is an electrical pin type connector located right above this part but i cant figure out how to disconnect it or if this is even the right part.
    where do i go from here, other than to real mechanic?
    thanks
     
  2. ernie

    ernie Two Time F1 World Champ
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    That's the part. It unscrews, so just turn it counter clockwise to remove it. You will also want to follow that wire down under the gear box and check the connection there.

    Now if those check out fine then I would have a look at the connection on the back of the speedo. There are two screws on the bottom corners of the instrument housing. Remove those, then lower the stearing column all the way down. Now grab ahold of the sides of the housing and lift it straight up. You will now have access to the connections on the back of the speedo.
     
  3. No Doubt

    No Doubt Six Time F1 World Champ
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    May 21, 2005
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    The electrical connection for the sending unit UNSCREWS?!

    Yet another day that I learn something new about my car.

    Thanks!


    (I guess...)

    OK, kidding...thanks for real.
     
  4. fmomen

    fmomen Karting

    Oct 4, 2004
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    india
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    faisal
    I have a speedometer of a 94, 348 ts. If your interested, pm me.
     
  5. 95spiderman

    95spiderman F1 Veteran
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    thanks for help but still having trouble.

    this electrical connector doesnt seem like a speedo cable. is similar to what a printer cable looks like with many small pins in a male/female relation. i dont think it can unscrew but should un plug. i cant get it un pluged though.

    thanks again
     
  6. Miltonian

    Miltonian F1 Veteran

    Dec 11, 2002
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    I've never dug into the speedometer system on the 348, so I'm not an expert, but I can tell you that the speedometer is totally electronic, there is no conventional rotating cable involved. The sending unit (called a "pulse sensor" in the parts book) is on the left side cover of the transaxle, just below and in front of the left inner CV joint, and it can be seen and reached from above.

    The piece by the shock tower is apparently just a multi-pin connector for the engine compartment wiring, and it includes the wires for the speedometer (I think), but it is NOT the sending unit. Your problem is most likely down there at the sensor on the transaxle case (part # 116987, tav 28, item 29).
     
  7. Ricambi America

    Ricambi America F1 World Champ
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  8. 95spiderman

    95spiderman F1 Veteran
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    i never cease to be amazed at how much you guys do to help out esp. with the drawing!

    could anyone direct me to the sending unit in relation to the metal clutch connector that is below the electrical connector? since i know i can find these two things maybe i can get where i want from there

    many thanks
     
  9. Miltonian

    Miltonian F1 Veteran

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    #9 Miltonian, Sep 30, 2005
    Last edited by a moderator: Sep 7, 2017
    Spiderman; I tried to find a picture in one of my books that would point you right to the speedo sensor, but I couldn't find a good one. I just took the attached picture, which might help, but it isn't easy to get a good shot.

    In the picture, the front of the car is to the left. The ignition coil, where the spark plug wires attach, is at the bottom of the picture. The end of the yellow tape measure is sitting right on the speedo sensor. It's just below the rubber CV joint (axle) boot. There is a plug for the sensor wires just a couple of inches from the sensor. If you look at the link in Daniel's post, you'll see what the sensor looks like. It screws right into the side cover for the transaxle. About all you can do without replacing it is to make sure that it is screwed in securely and that the wire connection is clean and tight. You might need to buy or borrow an appropriate tool to remove the sensor, but it isn't rocket science.
    Image Unavailable, Please Login
     
  10. Ricambi America

    Ricambi America F1 World Champ
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    It's a "brotherhood" thing.
     
  11. Miltonian

    Miltonian F1 Veteran

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    #11 Miltonian, Sep 30, 2005
    Last edited by a moderator: Sep 7, 2017
  12. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
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    I guess the poolstick won't fit under the car thus the use of the measuring tape....

    Jeff knows all the tricks! :)
     
  13. ernie

    ernie Two Time F1 World Champ
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    LOL I was thinking the same thing. The pool stick is famous.
     
  14. ernie

    ernie Two Time F1 World Champ
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    Okay you had me scratching my head so I just when out and UNSCREWED the cable on my car. The whole cable does not turn, just the plastic fastener. There is a ribbed fastener at the end of the connector. Not the part that has the cable coming out the back of it, the fastern is in front of that. As you unscrew it the connector gets unplugged. SO yes it get's unplegged but you have to turn the screw to unplug it.
     
  15. 95spiderman

    95spiderman F1 Veteran
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    ok this looks promising! i will look again tomorrow and probably say i fixed it even if i didnt since you all went to such lengths to try and help.
     
  16. 95spiderman

    95spiderman F1 Veteran
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    yes! i finally figured it out. there is a connector coming out of the screw-in piece that had a broken clip. i disconnected it, cleaned it and duct taped it together. so far so good. thanks to everyone.
     
  17. ernie

    ernie Two Time F1 World Champ
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    Glad to be of help.
     
  18. PassionIsFerrari

    PassionIsFerrari Formula 3

    Aug 15, 2004
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    I was degreasing my motor today and saw the piece that you are talking about, I shot it with some contact cleaner too since my speedo every once in a while starts acting up...

    My question...

    If all you have to do is unscrew this connector to disable the speedo...how the heck do you know if any Ferrari really has the miles it says it does? I mean to unscrew that piece is ridiculously easy.
     
  19. ernie

    ernie Two Time F1 World Champ
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    BINGO!!!!

    There actually is a way to tell IF the battery hasn't been unplugged. If the speedo looses signal it will give the ECUs a code. But, if the battery gets disconnected then the codes will be cleared.

    It would not surprise me one bit if this has been done in the past. It is just way to easy to do.
     
  20. UK348

    UK348 Rookie

    Mar 8, 2010
    4
    I have an intermittent speedo and have read this thread and checked all the conections as advised. It starts after about 20 miles with the needle fluctuating around the 30 mph figure but with the milometer still working,after about 5 miles it all stops.If the car is left for about 10 mins then the speedo comes back to life but still fluctuates for a while before stopping again.Ifthe car is left for an hour or so all is restored untill another 20 miles go by when the process starts again. Is it possible that the sender unit breaks down with the high heat around it? or is it something else ? any ideas please. Thanks
     
  21. notbostrom

    notbostrom Formula Junior

    May 8, 2006
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    Ben
    given the talk about altering recorded miles the mod might want to delete this thread once the OP's problem is solved? Not the kind of thing we want coming up in a google search??
     
  22. mcooper

    mcooper Karting

    May 13, 2009
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    I had this issue several months ago. It had the same symptoms for quite a while then finally went out. Most posts on here indicated that changing the sending unit would probably solve the problem, but my problem was different. I did replace the sending unit, but it did not correct the problem. In mine, the circuit board was fried within the speedo. It could have just been a circuit board problem, but we also suspect it could have been related to the frayed wires shorting out between the driver door and the driver front fender. Where all the micro connectors plug in.

    In any case, I got the wire connections fixed and had to replace my speedo.
     
  23. Jeff Pintler

    Jeff Pintler Formula Junior
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    Jul 20, 2005
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    So how do we correct for speedo error? One of my cars reads 5 over and the other reads 10 over. (not trying to hijack the thread)

    Jeff Pintler
    89 348tb, 86 tr, 99 360 3pedal
     
  24. FandLcars

    FandLcars F1 Rookie

    Aug 6, 2006
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    Tire size (diameter) will make a difference, so if you have different wheels/tires than OEM, differences in diameter will cause errors.
     
  25. UK348

    UK348 Rookie

    Mar 8, 2010
    4
    After much fiddling all to no avail decided to change sender unit,BINGO works perfectly now.Im told by people who are far more knowledgable than me that the thin wires get very brittle with the immense heat generated down there and as a result tend to expand and cause bad connections which give the symptoms I experienced.Seems reasonable to me but anyway problem solved.
     

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