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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    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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    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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    Scot McPherson Senior Member

    The usually and customary way to handle this is to note meter change and the mileage in the ships logs.
     
    philSweet likes this.
  4. missinginaction
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    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
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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
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    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
     
  7. RzrbackAV
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    Location: Fayetteville, AR

    RzrbackAV New Member

    Can’t seem to get my signal generator to output anything that raises the RPM’s to get the hours to register. No matter what pins I switch to
     
  8. missinginaction
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    missinginaction Senior Member

    Remember to supply 12 volts to the signal generator and the tachometer separately. If you're using the same signal generator I used I don't see why it wouldn't work. See my post #6 above and let me know please.
     
  9. Steve parisi
    Joined: Feb 2021
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    Location: Long Island ny ,south shore

    Steve parisi New Member

    Hello and thank you for your quick reply. I’m trying to use the signal gen to advance the hours on my new faria Chesapeake .can you possibly send a wiring diagram , so i have the generator.the second group of pins should be jumped ,next 12 volt power to vcc then black to ground ,then out to signals on tach.also power tach separately and from 12 volt + to batt terminal on tach and 12 volt neg to ground on tach . Thank you again for your help ,steve
     
  10. missinginaction
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    missinginaction Senior Member

    Hi Steve and welcome to the forums,

    You're really testing my memory. The original post and the second of this thread are a little over 4 years old. Nevertheless the principles haven't changed. I don't have a schematic but reading your post you appear to have a good understanding of this. I just used a little 2 amp 12 volt DC power supply that I've had for decades. I found that test leads worked great for making the connections. I wish I could be more help but I think you've got it. Have you tried this yet and is your tach registering hours and showing some RPM reading?

    MIA
     
  11. Brad808
    Joined: Aug 2022
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    Location: Hawaii

    Brad808 New Member

    Hi, I know this thread is quite old and I understand if you don't remember much about the process. This is the only place I've found any info on setting the correct time once replacing a tachometer. I have twin honda 50's and had to replace one tachometer. The link provided on amazon for the device is no longer available to purchase. 2 questions. Do you think it's possible to do to Honda's and if so what else can I use to increase the time? It says zero currently and I want it to say 500 hrs so it matches with the other tachometer. Thank you.

    Brad.
     
  12. rxcomposite
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    rxcomposite Senior Member

    To reply to an old thread, most hour meter/odometer/speedometer is electronic and there is a little 8 pin IC inside the board. This is read only memory but can be reprogrammed with a few simple electronic tools. The problem is those who do it are no longer practicing as they work only on cars and it is now illegal to reprogram mileage on cars. Search YouTube, especially on the topic about instrument panel/reprogramming odometer.
     
  13. Brad808
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    Brad808 New Member

    Thank you!!
     
  14. missinginaction
    Joined: Aug 2007
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    missinginaction Senior Member

    I'd need to see the gauge(s). That said though, I would think that they all pretty much work the same. You have the replacement tachometer. Does it have a 12 volt positive terminal (that powers the gauge), a ground terminal and a signal terminal? If it does I'd think that you should be able to add time to it. Hopefully you'll understand my earlier posts. I had to experiment with the signal generator in order to get a pulse to the tach. Once I got the tach to register RPM (it didn't matter how many RPM's, I just needed to get a signal to the tach) it registered time on the hour meter.

    This one is a little more expensive then the one I used (isn't everything these days?) but would work in this situation I think.

    https://www.amazon.com/dp/B07R45229...aWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

    I'm no electronics expert but I do know that "VCC" stands for "voltage common collector". Attach a test lead to the VCC terminal from your 12 volt power source. I believe you could even use a little 9 volt battery or other set up if you wanted to as the input voltage is from 5 to 15 volts. The ground goes to, well ground and the output would connect to the signal terminal on your tach. You might have to play around with the jumpers to get a signal that registers RPM on the tach. I didn't have any instructions with the signal generators I was using so I just played around with it until it got the tach registering RPM.

    Keep in mind that you need to connect power to the little signal generator AND power to the tach. You would use a couple of test leads to get power and ground to the signal generator. THEN connect the output of the signal generator to the tach with a third test lead. You ALSO need to send 12 volts to the tach and ground the tach back to the 12 volt ground.

    https://www.amazon.com/KAIWEETS-Ele.../132-4898611-7542631?pd_rd_i=B08DY7YVGK&psc=1

    Hopefully this will get you on the right track. Good Luck.

    MIA
     

  15. rxcomposite
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    rxcomposite Senior Member

    This is typical of ODO reprogramming. Requires identifying the IC, reading the Hexa codes stored in it then reprogramming. To a practitioner, it is easy but the level of difficulty arises when the IC is to be desoldered. Some requires only a clip on leads but needs an electronic interface which cost about 10-$15.

     
    Last edited: Aug 4, 2022
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