FV342 - 12v Systems - no power unless on shore/generator power

Hi all - I have a perplexing issue. While trying to drop anchor, (not on generator) I lost all 12V Systems. The 12V systems will now only work on generator power or shore power. I have checked every breaker - none are tripped. Is there a fuse somewhere that I am missing - with the exception of running down every 12v line, I feel I have looked everywhere. Any help would be appreciated! Thanks
Comments
Boat Name: King Kong
"Boat + Water = Fun"
If it is a battery: replace both and of the similar kind. Depending on your charger you could switch to AGM types.
PC BYC, Holland, MI
I don't think it's the battery.....he would have noticed that it was slowing down. My bet is that he has a loose or bad connection. Sort of like a bad ground on a car....you turn the key and the starter clicks and then there is no more power. Windless is a high amperage draw and a bad connection would act just as stated.