Boat power cuts off when I turn the key

[bman1bpm]

I've been having an intermittent issue with my boat. It is a 2001 Bayliner with a 5.0 Mercruiser, alpha 1 Thunderbolt V ignition.

Sometimes when I go to start the engine, usually on a cold start (with bilge blower running) as soon as I bump the starter all power to the boat is lost. Almost like it's tripping some kind of breaker (is there one?). If I turn off my main battery switch then turn it back on all goes back to normal and it starts fine. It has happened 4 times now. The batteries are strong, 3 seasons old and never have been run all the way down.

 

[alldodge]

You have corrosion or loose connection somewhere. Start at the battery switches, they may be corroded or even have some bad contacts. Then check all the other cables including grounds (most important, including where it attaches to the block). Remove them and shine up the contacts and ends to make them shine.

 

[bman1bpm]

Yeah, thought crossed my mind that maybe the main power switch is going bad since turning it on and off seems to fix it. Do boats have any kind of main breaker? The radio blower and everything cut off when it happens

 

[achris]

Yeah, thought crossed my mind that maybe the main power switch is going bad since turning it on and off seems to fix it. Do boats have any kind of main breaker? The radio blower and everything cut off when it happens

Sounds like the main battery switch is failing. Burnt/corroded contacts internally. Yes, the engine has a breaker, but it's not reset by turn power off and on again, if it trips you need to physically push the breaker to reset it.

Chris.....