Low voltage warning when starting boat

[NautiqueOasis]

I have gotten a low voltage warning when starting my '05 211; volt meter is reading below 12 volts but as soon as I rev up the engine the low voltage warning goes away. Suggestions??

[ski4evr]

I'm having the same issue. I charge the batteries before leaving the house, and by mid day, I have to have the engine running while running the pumps or the PP beeps at me when I start the boat until I rev the engine. I think it is the size of the power circuit to the dash. I have plans to change it to a more suitable size this winter.

[robertsmcfarland]

had that same problem once, it turned out to be a bad belt tensioner