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jiott
04-11-2018, 02:55 PM
Recently my 912uls tachometer digital reading (Dynon Skyview) started going erratic at high rpms. It would spike way up and then drop back to normal, then repeat at regular intervals, triggering an audible and visual "Overspeed" warning. I went to the installation manual, and also to the Dynon forums, and discovered that this specific problem was usually caused by the lack of a resistor in the tach wiring. In fact, the installation instructions had recommended a 60k ohm resistor be installed in the tach wiring, which I had missed when I did my install. Don't know why it worked fine for 600 hours, then decided to go unstable. I installed this resistor and now everything is back to stable readings.

I just mention this, because it can be easily missed, and it seems to be treated as a recommended option, rather than a must do. For those doing your own wiring, just do it up front when everything is easily accessible. Don't know if this applies to other brands of engine monitors, but just a heads up.

Frontier Fox
04-12-2018, 09:10 AM
Another great tip to remember.

Thank you Jim.

Joe G.