Battery parallel switch

[pschauss]

What is this switch supposed to do? Checking it with a test lamp, I can see that it is a momentary switch with an inputs from the port and starboard batteries (before the ignition switches). When I hold it in the on position it connects both inputs its output. IIRC, the wires are all #10 AWG. Although the label suggests that it allows you to start one engine with both batteries I don't see how it does that.

Thanks,

[Lars]

I believe the switch output should engage a relay/solenoid while pressed, paralleling the batteries in a situation where extra juice is needed for starting. Input to the switch comes from both batteries in order to ensure voltage to the relay if one battery is dead. However, if your boat has been rewired, chances are that the switch is no longer in use.

[Tooeez]

It allows you to use the battery on one side to start the opposite engine, if that side is dead. My 28 came from the factory with only one battery on each side, so this provides a way to jump a low battery without leaving the helm. It should be connected to a solenoid mounted between the engines on the forward engine room bulkhead.

[pschauss]

My master switches have four positions: Off, 1, 2, and "Both". Isn't the last position supposed to do the same thing as the battery parallel switch.

BTW, the guy who was showing the boat for the previous owner's daughter told me that he had been told to start and run the boat with both master switches in the "Both" position. Is that correct? My boat has only two batteries, in case that makes a difference.

thanks,

[Tony Meola]

Peter

Even though they are on both, that does not bring both batteries online to start an engine.

My old Cole Herse switches from the factory were the same way. When cranking the engines, when I threw over the switch you could tell both batteries were spinning the engine. It would spin faster.

If you follow the wires from the battery you will see them running to a solenoid. On my 75, the a solenoid was on the port side mounted on the forward bulkhead in the engine compartment. Easy to find it. It was the only solenoid there.

If you don't have the solenoid then someone rewired the boat.