Boat starts and runs fine, electrical all seems good, battery charges to 14-15v at speed so I'm thinking bad tach? It's original on the boat so it wouldn't surprise me...Just putting this out there...
How do you know the reading is wrong; are you checking with another tach? You could clean all connections on tach and then under the cowl; look for the gray wire and clean its connection. Maybe that's all that's wrong with it; my connections on the back of the tach were flaky and needed to cleaning to correct but my needle was moving all over the place. Good luck
Model is j90tlcim. The tach was working fine. Now when I shut it off it doesn't go to 0 just stays at about 1100, and goes to about 2000 when I start it. Connections are tight and clean.
It sure does sound like a bad tach, when you switch the key to the ON position do you get 12 Volts between the Purple & Black at the back of the tacho?
