battery/battery switch help

[Mcole1170]

Hi all
On my new to me sundancer 280, my port engine will not start on battery switch 2 position. But the starboard engiine will. Port 2 engine only starts on switch 1 position. My mechanic said it was battery. put a new one in and same thing.
I have two switches a 1/2/both switch and an on/off switch which im told is the house 12v battery
thanks

 

[Mcole1170]

ok so someone just said that the left 1/2/both is for the starboard and the house battery. and the right on/off is for the port.

 

[Mcole1170]

layout is one battery towards stern and 2 side by side towards bow. back battery is by itself. the 2 front batteries and tied together wiith one connected to generator

 

[Bt Doctur]

Usually you have a battery for each engine.So disconnect one battery + and see what works , then reconnect it and unhook up the other battery lead and see what works. Most systems combine a engine battery and house battery for one motor and a single battery for the other motor.
Personally I like a dedicated battery for each, engine, gen, and house

 

[techmitch]

Usually you have a battery for each engine.So disconnect one battery + and see what works , then reconnect it and unhook up the other battery lead and see what works. Most systems combine a engine battery and house battery for one motor and a single battery for the other motor.
Personally I like a dedicated battery for each, engine, gen, and house

Never, Ever, is it good advice to disconnect the positive cable first. The newer the boat, the more important/critical this!

True colors.

 

[JVM225]

Can you follow the cables from the switches to see which engines starters they go to and what goes to the genny?
Or, follow the ground cables from the batteries to see where they go?

 

[Lazy Daze]

What you were told in your second post is correct. There will be information in your manual about this if you wanted to read up on it.

 

[Mcole1170]

Thanks for all the info. I will trace the battery switch lines and see where they go

 

[Little Ducky]

Never, Ever, is it good advice to disconnect the positive cable first. The newer the boat, the more important/critical this!

True colors.

That's backwards....... Always the negative 1st.

 

[Bt Doctur]

Guys, never said disconnect while running , Said to disconnect one battery to see what works and what dosent . Then do the same for the other battery

 

[insfnds]

The ONLY reason you disconnect the negative battery first is in cars that are made of metal. If you are wrenching on the positive battery connection and you wrench hits the metal of the car, you have a arc-welder. Therefore disconnect the negative first (which it wont matter if you hit the metal of the car) then do the positive.

On a boat, it just doesn't matter...unless there is grounded metal near by.

Electrically, it doesn't matter which one you do first. As it is, the battery switch disconnects the positive lead anyway.

 

[Wylie_Tunes]

As long as you dont let the POS touch a ground, there is nothing wrong with taking the POS off 1st. If you think about it, every time you turn the battery switch(s) off, you are disconnecting the POS from all the electronics.