# Hour meter testing



## Markcamaro (May 6, 2018)

Hi tractor guys.
My S2554 stopped showing hrs. Any way to test it?
Thanks


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## Bob Driver (Nov 1, 2017)

Most hour meters have 2 terminals. 12VDC in and a ground. Test depends on how it's wired. Some are wired with the 12VDC supplied with the key in the run position and comes off the "R" terminal of the key switch. Forget and leave the key on, the hour meter keeps ticking.

Others run the hour meter wiring through a NO (normally open) switch tied into an oil pressure port (usually down around the filter). The way it's wired depends on if it's a 1-wire, or two-wire switch


*2-wire*
12VDC comes off the "R" terminal with the key at run and sends it to one terminal on the pressure switch. Oil pressure hits 5PSI, contacts in the switch close and the other terminal sends 12VDC to the meter. Meter only ticks if the engine is running.

*1-wire*
12VDC comes off the "R" terminal with the key at run and sends it directly to the hour meter. The oil pressure switch is tied into the GROUND wiring of the hour meter. Oil pressure hits 5PSI, a contact in the switch closes and grounds through the body of the switch to the block. That's why it's not a good idea to use Teflon tape, or sealer, on a single-terminal sensor switch (oil pressure, or temperature). No oil pressure, no hour meter running.

Why not just get an inductive hourmeter/tachometer? Wire just wraps around the spark plug lead. Only works when the engine is running. You can use the tach function to set working RPM, or idle speed. With a push of a button, you can read hours. $10 on Amazon









https://www.amazon.com/dp/B07MXXLXFP/ref=dp_cerb_1


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## Markcamaro (May 6, 2018)

Thanks for all that info. I think Ill take your advice and get one like you mention with tach feature


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