Why is this

[KEVMAR]

On my 1887 43 ft President in the galley next to the stairs is this switch . What is it and what does it do ?

 

[Wayfarer]

Maybe it’s an anti theft device. A second switch in a random location that cuts off power to the ignition?

 

[FF]

A blower switch?

 

[caltexflanc]

Where do its wires go?

 

[GFC]

Hmmmm, It says "Engine Switch" on the metal. I'd guess that's what it is and it would be easy to verify by switching it off and seeing if the engine starts.

 

[Comodave]

We don’t have anything like that on our 41’ President. Maybe a battery or ignition switch???

 

[ben2go]

That looks like a switch used to disconnect the power from the starter(s). I've seen this done on boats where the electrical system drains back through the alternator due to a bad diode in the alternator. A switch decouples the battery in some systems. A proper wiring job and alternator check would cure the need for the switch if it's even used now. Some alts charge the battery by back feeding the positive wire at the starter. I don't like this arrangement. I had it on an old Jeep and changed it after buying it. I'm not saying it's this way on your boat. Just one possibility.

 

[Comodave]

That switch looks like President original equipment to me. It is similar to some things on my boat so I don’t think it is an add on to fix some problem but rather something that President though was necessary but may have been taken out of service at some point. If it is still in service then just trace the wires to figure it out.

 

[twistedtree]

It looks to be three positions; Off, engine switch, On? If that’s the case my guess would be an ER ventilation blower that can be manually controlled (On and Off), or controlled by the engine switch, I.e on when the engine is on.

 

[kchace]

I have battery switches that look exactly like that