2008 Bayliner Tach rotating counter clockwise

[Evinrude Boater]

My neighbor's boat has a tach that rotates backwards to about 4,000 rpm regardless of speed. It goes back to zero when idling too. I know it's under warranty but that means pulling it out of the water and trailering an hour, leaving it, etc., etc.

 

[Silvertip]

Re: 2008 Bayliner Tach rotating counter clockwise

Check the wiring. There are three wires involved. +12V when the key is on, ground, and send ("S") terminal. Perhaps the +12V and ground are reversed.