3-way boat wiring?

droptopgeek

Recruit
Joined
Jul 17, 2007
Messages
4
Hello all I am a long time boater, first time owner and new to the forum.

Brief background:
I recently purchased a 28? 1976 Winner and have found myself in the middle of an unexpected project. Yes when I bought a 30 year old boat I knew there were going to be some projects but I didn?t expect the depth of the projects that my surveyor did not find. I have recently decided that a complete rewiring is the way to ensure that all will work as expected. The boat has duel control station one on the fly bridge and one on in the salon(ish). I am fairly handy and have done most of the engine tuning myself and am planning on doing all of the 12 volt system myself. I am knowledgeable with 12volt wiring in cars but I have never wanted to control my wipers from the back seat and hence the problem. I have asked several knowledgeable marine industry friends people at my local boat store but no one seams to have an idea of how to do this. I plan on having controls for items like the bilge blower, Bilge pump manuals, navigational lights, horn, etc at both stations and then other 12 volt items controlled only from the lower station. A great perk would be if I could insert the keys in the lower station then start and kill the engines from the upper station but that may be my next post.

The question:
Does anyone make a 12 volt 3-way switch and I don?t mean an on-off-on switch I mean a 3-way switch like what you would use in house wiring with a switch lead that runs between them. I would like to be able to turn on or off items from either station. I have been researching relays and possible electronic devices to do this but have not been able to find any help. Example I turn on the nav lights from the lower station and then drive all night to deliver the boat to its new home (this actually happened) then about ? hour after dawn I had to wake up my first mate to turn them off because all I could do from the upper station was flip a switch to send more power to the light. The way it is currently wired the starboard engine battery is the house battery this will be changed as well but for now lets start the circuit there from that point there are one positive and one negative lead (positive runs through a battery switch) running to each station then the positive leads run into a fuse block in the lower station and older console fuses in the upper station. From there they run to the switches at their respective station then on to the load. This works to allow them to be turned on from either station but they can not be turned off from one station if the other station has them on.

Any ideas would be greatly appreciated I can?t be the only person that wants to wire their boat this way can I?

Thanks all
Adam

:confused::confused::confused::confused::confused:
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: 3-way boat wiring?

If you don't care about the toggle positions relative to the on off status of the light (just like a 3 way in your home) then any pair of double pole, single throw toggles will work.

It simply requires one wire from one switch to the light, and one wire running from the other switch to the 12V source and two wires running between the switches. It's very simple. See diagram below. With it wired the way shown, if both toggles are in the same direction, the load is off, if they're in opposite directions, the load is on. Of course, this was just for drawing convenience... rotate either switch 180 degrees, and they'll be on when toggles are in same direction, and off when opposite.

If you want to know whether the light is on or not, from the bridge, you can send a wire from the light (yellow) connection back to the bridge to a status light or LED above the switch.

Good Luck!

3wayswitch.jpg
 

chuck_050382

Seaman Apprentice
Joined
Jun 4, 2007
Messages
46
Re: 3-way boat wiring?

Another way would to be to install relays for all items you wish to have dual sets of controls for and then switch simply engage the relay turning on accessory.
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: 3-way boat wiring?

Correct, but would require latching relays and 2 push buttons at each control location or "momentary-off-momentary" switches which fails his basic premise of "no on-off-on" switches.
 

droptopgeek

Recruit
Joined
Jul 17, 2007
Messages
4
Re: 3-way boat wiring?

can we go more in depth on the relay wiring. how would that work. I would like to keep it simple but relays would allow less total wiring would it not?

Thanks you guys have been very helpful.
 

QuadManiac

Petty Officer 1st Class
Joined
Jul 2, 2007
Messages
391
Re: 3-way boat wiring?

Relays would reqire more wiring. Relay at the load, with power and ground to it, switched power from it to the load, two wires from each switch station. At each switching station (bridge, cabin, etc.) you would need power, and two wires going to each relay. Each switch station would require either 2 push buttons or a momentary-off-momentary switch. If you want a load indicator, that's another wire from the relay to the switch station, plus a ground.

You could put the relay at one of the switch stations, and just pass the load wire to the light, etc. That would reduce the total wiring a bit.

Advantage of relays is you can add as many control stations as you'd like. Using switches, as shown earlier, limits you to 2 control stations.

LatchingRelayWiring.jpg
 
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