Intermittent tachometer

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • RickR90s
    • Jul 2014
    • 15

    • Detroit

    • '92

    Intermittent tachometer

    Boat is a '91 Nautique with the PCM Ford 351 motor. The VDO tachometer has been working intermittently for awhile so I took the dash apart to investigate further. There are three wires going to the tach.
    Purple to the + terminal
    Gray to the SGL (Signal) terminal
    Black to the - terminal

    I pulled them all off and cleaned the male spades on the tach and made sure everything was clean and tight. I also fired up the motor to check the voltages and across the +/- I get about 13volts at idle. And the signal to ground connection shows about 6vdc. I have a nice Fluke meter with the bottom graph so I was expecting a pulsed signal but instead it showed a constant 6vdc.

    I also checked the connection block where the signal wires plugs in and cleaned those connections.

    In any case, I installed everything and now it doesn't work at all.



    Any insight would be appreciated.

    thanks,

    RickR90s
  • east tx skier
    1,000 Post Club Member
    • Apr 2005
    • 1561

    • Tyler, TX


    #2
    If it has that little switch on the back, turn it through each position a few times and put it back on V8 or 8V or whatever it is. Worked with mine.
    1998 Ski Nautique (Red/Silver Cloud), GT-40, Perfect Pass Stargazer 8.0z (Zbox), Acme #422, Tunable Rudder.

    Comment

    • Orlandoguy82
      • Oct 2013
      • 4

      • Orlando

      • 1997 Sport Nautique Gt-40

      #3
      That truck of turning from 6cly to 8 cly worked for mine too


      Sent from my iPhone using Tapatalk

      Comment

      • RickR90s
        • Jul 2014
        • 15

        • Detroit

        • '92

        #4
        Originally posted by Orlandoguy82 View Post
        That truck of turning from 6cly to 8 cly worked for mine too


        Sent from my iPhone using Tapatalk
        thanks guys, I think I'll try that.

        Comment

        • RickR90s
          • Jul 2014
          • 15

          • Detroit

          • '92

          #5
          Ok, this gauge has two switches/adjustments. One if for the 4,6,8 cylinder selection. The other adjustment appears to be a range adjuster. In either case, playing with both with the engine running did not solve the problem. Any other ideas would be appreciated.

          Like I said in my previous post, I am getting 12vdc across the two outside terminals. it's the middle SGL terminal that has me confused.

          Comment

          • jhersey29
            • Nov 2013
            • 330

            • Colorado

            • 1971 Correct Craft Mustang 1988 Ski Nautique 1992 Ski Nautique 1999 Ski Nautique

            #6
            Use ohm meter on rpm sender and check the sender.
            Sent from my RM-877_nam_att_205 using Tapatalk

            Comment

            Working...
            X