Mondial Odometer stopped turning, Speedo and tach running flawless | FerrariChat

Mondial Odometer stopped turning, Speedo and tach running flawless

Discussion in 'Mondial' started by braq, Apr 16, 2015.

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  1. braq

    braq Karting

    Mar 29, 2010
    225
    Hill Island
    Full Name:
    Paul XXXcX
    Hello all,

    two days ago I picked up my 83 QV coupe from the Autoport in Halifax, NS and drove it via Edmundston to Ontario. Around Montreal the odometer stopped working, however speedo and tach operate flawless, which, after some reading, led me to believe the sensor at the transmission should be intact and I shall investigate the odometer itself (please correct me if I am wrong in assuming so). Some more reading suggests that the bezels pops out, carefully prying on the side of the rectangular odometer housing does not suggest it comes out that way. Any hints on how to remove the odometer box itself are highly appreciated.

    Cheers

    braq
     
  2. afterburner

    afterburner F1 Rookie
    Silver Subscribed

    Jun 20, 2008
    3,197
    Hong Kong
    Braq, the speedo signal does go from the sensor to the milage counter and to the speedo, so in your case, it works.
    Pull off towards you the tach finisher, remove the 4 corner screws and pull out the tach. The clock/odo/4-gauge unit flips out around the hooks on the side to the centre tunnel.
    You can then remove the clock/odo unit from the 4-gauge unit.
    The clock is held by screws and can be disconnected from the PCB covering the odo unit.
    Next comes the PCB and finally the Odo unit. Dismantle it and inspect. Good luck!
     
  3. braq

    braq Karting

    Mar 29, 2010
    225
    Hill Island
    Full Name:
    Paul XXXcX
    Afterburner, very very much appreciated, will do later today and update. I like the look of the mechanical and electrical parts, looks like the interior of RC model boats I buildt in the 80s ;-)

    cheers

    braq
     
  4. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
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  5. Clike

    Clike Rookie

    Sep 26, 2008
    34
    Ogden, UT
    Full Name:
    Clark
    So to bench test the electric odometer motor, if 12 volts are applied, will the motor spin continuously, or with little jumps as though it is receiving the signal from the sensor? Which wires from the plug-in harness are supposed to have voltage that control the mileage counter to make sure that it is receiving the signal?
     
  6. AUDIO RESEARCH

    AUDIO RESEARCH Formula Junior

    Feb 11, 2009
    350
    PHILIPPINES
    Full Name:
    LUIGI RAYMUND LIRA
    Hi to all,

    I have the same problem .How I wish I can tackle this problem also my odometer stopped a long time ago . Thanks for the photo's it will help my electronic tech when I ask him to fix the odometer.

    audio research
     
  7. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
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    Hong Kong
    #8 afterburner, Apr 17, 2015
    Last edited by a moderator: Sep 7, 2017
    If I believe that motor will spin continuously. The entire system is based on the pulses sent by the sensor.

    Have a look at the attached diagram to identify the wires and follow their paths on the PCB (which I have reversed to facilitate its lecture).
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  8. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
    3,197
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    Braq, please understand I cannot guarantee that my information is correct - use at it at you own risk...
     
  9. braq

    braq Karting

    Mar 29, 2010
    225
    Hill Island
    Full Name:
    Paul XXXcX
    Again, lots of thanks and is that the original Pioneer radio in the 1st picture?
    So I found everything as described, could verify the perm, ignition, lights on voltage at around 11.4V (with engine off), no obvious burnt electronics or cables, no voltage regulator or uChip getting hot. Confirmed diodes at 0.7V (escept for one at 1.6V) and the resistor values (for all of that, I completely switched off the ground using the switch next to the battery). So the next logical step for me is to apply some 12V to the odo unit itself, that would be orange (gnd?) and red (12V?) from the last picture.
    I forgot to mention earlier, the clock display flickers randomly (even with car standing still and engine shut off), only way to get it "relaxed" is to press button "C" so the setting sequence is started, once pressed the 3rd time and coming back to regular mode it appears to be switching at high frequency between time and all digits lit.

    cheers

    braq
     
  10. kev101

    kev101 Rookie

    Jul 18, 2011
    4
    I'm having the same problem with my mondial 8. I had taken the unit out and had it sent to two auto elections to find the problem. Every other instrument works even the service light came on recently. Thinking of buying a new unit from superformance for £254 but it is for a US qv model and they could not confirm if it will be compatible. The units brackets are opposite lengths as my car is right hand drive and don't know if electrical components are the same or different. If the electrical comments are the same I could swap the casing so it will fit back in the dash. Hopefully someone will have a solution
     
  11. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
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    #12 afterburner, Apr 18, 2015
    Last edited by a moderator: Sep 7, 2017
    Welcome, and yes, it is the original radio (the Mondial was the first Ferrari with a factory-fitted radio)

    I don't know. Put power on the check the polarity with a multimeter? Then, I would probably unsolder the wires from the PCB to test with 12V.

    The intermittent clock on my car was due to cold solder points of the clock connection socket on the PCB. It looked OK (see pic), but with the connector off, the socket moved when touched. Re-soldering solved the clock issues. The connector being vertical I think vibration caused it to break free over time.
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  12. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
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    Odo or clock?

    So the speed sensor works.

    The clock is symmetrical is the same. The odo unit is also translated to the RHD, not symmetrized. My gut feeling is that the internals are identical, and only the mounting frame is LHD/RHD.
     
  13. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    Technical threads like this are the best! Thanks
     
  14. kev101

    kev101 Rookie

    Jul 18, 2011
    4
    The odo stoped working and the clock works fine. Had electrical components replaced on the unit and still not working. Only way to know now is to replace unit and if that does not work not to sure where to go from their.
     
  15. afterburner

    afterburner F1 Rookie
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    Jun 20, 2008
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    Like the OP's original problem then.

    Do you know which ones?

    You could check out all the wires like the OP did just to see if there is something not working. Chances the odo motor is broken are slim. Test this one and if it works and all the wires are giving you a signal, then it must be the PCB...
     
  16. kev101

    kev101 Rookie

    Jul 18, 2011
    4
    Thanks for all the info I will use this when testing the unit again. If it is the pcb I presume that it can not be replaced
     
  17. alhbln

    alhbln Formula 3
    Consultant Owner

    Mar 4, 2008
    1,749
    Berlin, Germany
    Full Name:
    Adrian
    Braq,

    If you can't get it fixed you could send it to me and i'll have a look.

    Good luck,
    Adrian
     
  18. kev101

    kev101 Rookie

    Jul 18, 2011
    4
    #19 kev101, May 25, 2015
    Last edited by a moderator: Sep 7, 2017
    I sent the unit again for repairs and printed off all the information on this forum. I got the unit back and still not working. I have purchased a brand new unit from Superformance: Ferrari Parts for 246, 308, 348, 355, 360 and all of the Ferrari range . The unit is for a US mondial qv but it works in my Euro mondial 8. The only diffrence is you have to take the component apart and put them in to the old mounting frame as it wont fit the right hand drive model. The new unit also does not come with a clock. The part number on the site is 120373. Hope this helps someone else with trouble. I have also had the unit adjusted to the real millage of the car as the service light came on only recently.
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  19. mistral95

    mistral95 Rookie

    Jun 19, 2015
    23
    Paris France
    #20 mistral95, Nov 3, 2015
    Last edited by a moderator: Sep 7, 2017
    I am trying to remove the PCB, to replace burnt transistor for light dimmer.
    But the PCB does not come out from the plastic unit.
    I removed the glue (silicone) at upper edges, but PCB still blocked inside.
    How did you remove it?

    My PCB has slightly different arrangement , mine is a 1986 Mondial 3.2 Euro:
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  20. afterburner

    afterburner F1 Rookie
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    mistral95, I think (= I am not sure) you need to remove the rheostat knob on the front face first. Then remove the white hot glue blobs in the corners...
     
  21. mistral95

    mistral95 Rookie

    Jun 19, 2015
    23
    Paris France
    Thank you Afterburner: I will try that way
     
  22. Milkyboy

    Milkyboy Karting

    Jun 23, 2015
    61
    This thread highlights a couple of things for me:
    - The remarkable dedication to solving problems and admirable willingness to help others of some on this forum. Genuinely uplifting to see/know
    - The likelihood of the mileage on any ferrari of this period being genuine, irrespective of unscrupulous former owners!
     
  23. Anthony bentley

    Anthony bentley Formula Junior

    May 20, 2006
    540
    London
    Full Name:
    Anthony Bentley
    Ok so I have an issue with my odometer (intermittent) my digital clock doesn't work at all (it did the first night I had the car). I tried pulling it out yesterday but the wires disappeared into the dash, I notice in this instance there are spade and bullet connectors, did you cut the wires or is this same in my case and I'm not looking far enough?
    All the other instruments work correctly.
     
  24. stekkefun4

    stekkefun4 Formula 3
    BANNED

    Nov 22, 2006
    2,232
    Belgium - Europe
    The wires disappeared in the dash? Maybe you pulled the unit too strongly without having detached the cables under the panel first?
     

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