2007 G1000 Ovation w/Dual Tachs, E.I. Tach Gone Wonky!

[Jeff_S]

Hey all. I've got one of the early G1000 Ovations that has the extra E.I. tachometer in the lower left portion of the panel. I've heard that this was required during early certification as the G1000 tach wasn't certified yet and this was the "official" tach.  Don't know if that's true or not. At any rate, lately that E.I. tach has gone wonky on me, showing very radical readings both higher and lower than what the G1000 is showing, although usually within 10 minutes of flight it settles down.  I suspect corrosion, which here in Florida seems to be my #1 culprit whenever I suspect electronic weirdness.  So now my question: are there individual pickups for each tach in the system, or is there one pickup that is then split somewhere to feed both the E.I. and the G1000?  In either case, where would I look for corrosion in the connection to the E.I.?

Appreciate your thoughts...thanks!

Jeff

[buddy]

If your G1000 now shows 2700 RPM as a red line on its tachometer then I don’t think you need the E.I. tachometer any more. I removed mine after a software update years ago.

[Schllc]

Yep, merely requires the software update to eliminate the extra tach.