Overheating 2009 supra launch 21v

[Smitty71]

Had my boat winterized and first day out. Battery needed a charge of course, but WAS NOT FULLY CHARGED when we left for the lake. Started well and ran fine but no accessories worked including ballast fill, stereo and then the boat started over heating. I assume I just need to fully charge the batteries but looking for some ideas. Thanks. Complete moron mechanic here.

[Mischief IV]

I’d check impeller first for the over heating issue along with the thermostat if need be.
If accessories aren’t working, I’d be looking a breaker or two that has tripped.

[michael hunter]

Pull the dipstick and make sure there is no water in the oil?

[docdrs]

Can you give us more info as to when, how , it overheats. How long have you had the boat

[sailnaked6842]

When the engine is running you'll always have the voltage you need to power the gauges unless the alternator is going out but that won't have anything to do with the overheating because the water pump is mechanically connected to the engine. If the engine is spinning then so is the pump.

Was there much water in the bilge? I've gotten hot because a hose blew off. You could also get warm if there's a plug that hasn't been screwed back in.

Lastly there's the thermostat test which is pretty easy. Pull the thermostat out, place it in water on the stove, stick a meat thermometer in the water, and turn on full. When the thermostat starts moving look at the temperature, and it should be around 165°F. If it's not opening then the thermometer is stuck