308 gt4 speedo problem | FerrariChat
Buy

308 gt4 speedo problem

Discussion in 'Technical Q&A' started by carnutvic, Nov 15, 2005.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. carnutvic

    carnutvic Karting

    Jan 30, 2005
    137
    ellicott city md
    Full Name:
    victor tamini
    #1 carnutvic, Nov 15, 2005
    i have a 1974 308 gt4 and the speedometer will read (relatively)accurate up to about 50 mph and then it drops off to 20 mph and kinda bounces around.anyone had this problem?
     
  2. gerritv

    gerritv Formula 3

    Jun 18, 2001
    1,400
    St Catharines
    Full Name:
    Gerrit
    #2 gerritv, Nov 15, 2005
    Hi
    Most likely this is a loose connection (at sender end on transmission) or it is a defective sender. T Rutlands probably have them, as do Ferrari of UK and Superfomrance in UK.

    Gerrit
    http://dino308gt4.com
     
  3. carnutvic

    carnutvic Karting

    Jan 30, 2005
    137
    ellicott city md
    Full Name:
    victor tamini
    #3 carnutvic, Nov 15, 2005
    thanks Gerrit.i will check it tomorrow
     
  4. carnutvic

    carnutvic Karting

    Jan 30, 2005
    137
    ellicott city md
    Full Name:
    victor tamini
    #4 carnutvic, Nov 15, 2005
    can the sender be bench tested?
     
  5. gerritv

    gerritv Formula 3

    Jun 18, 2001
    1,400
    St Catharines
    Full Name:
    Gerrit
    #5 gerritv, Nov 16, 2005
    Yes, you will need a +12V source and a small circuit consisting of a pullup resistor and capacitor. I don't have the specific circuit values with me, will post tonight.

    Gerrit
    http://dino308gt4.com
     
  6. branko

    branko F1 Rookie
    Owner

    Mar 17, 2003
    3,710
    Birmingham, Alabama
    Full Name:
    Branko Medenica
    #6 branko, Nov 19, 2005
    You are going to laugh but have you tapped the glass? Mine went to zero and I tapped the glass and it started to work again. Go figure! And it still works.
     
  7. carnutvic

    carnutvic Karting

    Jan 30, 2005
    137
    ellicott city md
    Full Name:
    victor tamini
    #7 carnutvic, Nov 19, 2005
    it always works up to 50 mph and then drops off.it is very consistant in its operation so i am going to try a new speed sensor.
     

Share This Page