Adjusting time on a replacement tachometer/hour meter

Discussion in 'OnBoard Electronics & Controls' started by missinginaction, Jan 7, 2017.

  1. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    I'm replacing a defective Faria Tachometer/Hour Meter in my lower helm. The wiring for this instrument is simple. + (batt), ground and a signal wire from the ignition system. I run an older boat and still use a simple points and condenser ignition. It works fine.

    The hour meter portion of the tach requires a signal from the ignition system in order to record hours. In other words simply turning the key "on" won't record any time on the meter. The engine actually has to be running and the tachometer reading engine RPM.

    I'd like to match up the new replacement tach with the one on the upper helm. So, I'll need to add some hours.

    I believe a signal generator will allow me to do this on the workbench. For a couple of bucks I ordered a simple unit from Amazon. The unit has no instructions and while I've become a pretty good boat builder, I'm by no means an electronics technician.

    Here is a link to the signal generator.

    https://www.amazon.com/TOOGOO-Squar...798984&sr=8-5&keywords=ne555 signal generator

    I see from reviews that someone used this item as I want to and for a couple of dollars it's worth a try.

    My question is how do I configure the signal generator? I don't have an oscilloscope. There are 4 sets of jumpers that I can use. I don't know which pins I should jump.

    Can anyone shed a little light on this for me. I just don't want to damage my tach by doing something I shouldn't.

    Regards,

    MIA
     
  2. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    Well I finally had a chance to try out the signal generator mentioned in the post above.

    I was able to answer my own question.

    If you look at the photos of the generator you'll see that there are 4 jumpable pins in the center of the board. The board ships with the jumper installed on the top two pins. I experimented and found that when I moved the jumper to the second set of pins, one down from the top, I was able to generate a signal that caused my tach to register about 1550 RPM.

    At this point my hour meter began to record time. And.....at this time, the little signal generator cost $2.82 and shipped free. This is about the least expensive "fix" I'll ever make on my boat.

    So it works. Hopefully this will help someone else set a replacement tachometer.

    MIA
     
  3. Scot McPherson
    Joined: Jan 2017
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    Location: New England

    Scot McPherson Senior Member

    The usually and customary way to handle this is to note meter change and the mileage in the ships logs.
     
  4. missinginaction
    Joined: Aug 2007
    Posts: 687
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    Location: New York

    missinginaction Senior Member

    Really? Well, I suppose that's an option but why not synchronize both meters and not have to worry about hours in the log? Scot, on old style meters synchronization was easy but the newer meters (such as the Farias I'm using) work differently.

    For a couple of bucks and a little time in the off season I'd rather my hour meters match up.

    But hey, we're all different aren't we?

    Regards,

    MIA
     
  5. RzrbackAV
    Joined: Jul 2018
    Posts: 1
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    Location: Fayetteville, AR

    RzrbackAV New Member

    Sorry to bring up an old thread, but you simply fed 12V DC through the signal generator to the BATT and GND connections on the Tach/Hourmeter?

    Thx.
     

  6. missinginaction
    Joined: Aug 2007
    Posts: 687
    Likes: 40, Points: 28, Legacy Rep: 512
    Location: New York

    missinginaction Senior Member

    You're testing my memory Rzr. If I remember correctly VCC (on the signal generator) stands for "voltage common collector". This is where your 12 volt dc positive feed connects. "Gnd" is of course ground and "Out" goes to the ignition sensor on your tachometer. You have to supply power to the tachometer separately . You can use the same bench top power supply. At the tachometer you'll have a positive and ground supplying power and a single connection to the signal terminal that is coming from the signal generators output. I set the jumpers one tier down from the top and the signal generator registered 1500 RPM on my tach. Hours then began registering. Hope this helps you out.

    Regards and welcome to the forum,

    MIA
     
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