On owners forum an issue was raised re our tach's pegging out and then going to zero while running the motor
with the battery charger
on. There were comments that running the engine
with the charger
on was not good for the alternator
and could be causing the tach to malfunction
This was the first time i heard of this although my tach has done the same thing but also has done it while motoring away from the dock
. After an initial occurrence or two it settles back down reads fine after that.
My assumption was i need to check my connections, get a new tach, etc. The engine
make would be either Universal 35 or Yanmar
on our sailboats of recent vintage.
Our's is a small forum and i know there is a lot more expertise and experience here.