Tach problem on 2008 Beneteau 40

[Captpete12]

My tach is pegged all the way clockwise, beyond max. I seem to recall threads about this problem in the past. Time for a new tach?

 

[GWG]

I had this problem intermittently, and it seems to have gone away. As far as i can tell, no adverse impact. I believe the tach works off the alternator.