What to do with the extra wire

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thesaintlyone

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So my whole boat is set up with a two wire system i.e. Earth and Live the Earth wires run to a Bus Bar and the Live wires go to the Switch Panel.

However the Mast Tri-Color and Anchor Light perched on top of it both have Three wires so what do I attach this extra wire too.........

I do have a blue sea fuse block installed but so far havent actually attached anything to it

http://www.tcschandlery.co.uk/blue-sea-systems-st-blade-fuse-block-12-circuits-with-negative-bus-and-cover/p8677?gclid=CjwKCAjwuvjNBRBPEiwApYq0zhy7aZHuoucHtQ-1YOrlj9rQl3e4wmVW8AFXKxsCYnEwyK0VX-ZFKhoCwUUQAvD_BwE
 
Do you have 3 wires from both the Tricolour and the anchor light - i.e. 6 in total ?

Or do you have a combine Tricolour and Anchor light with just 3 wires.?

Make / model / pictures may help us diagnose
 
So its a Tri-Color looks like an Aqua Signal and an Anchor Light placed on top of it so two cables 6 wires in Total. Mast is up at the mo so difficult to get a good look
 
thesaintlyone said:
So its a Tri-Color looks like an Aqua Signal and an Anchor Light placed on top of it so two cables 6 wires in Total. Mast is up at the mo so difficult to get a good look
Click to expand...
Why are there 6 wires in total. Surely you only need two twin core flexible cables, a positive and a negative to each light, at most, making a total of four wires.

Earths, lives and neutrals apply to your240 volt shore power system. Your 12 volt DC system has only a positive and a negative.

It might even be possible to use a common negative for the tri-white assembly, which would mean you could manage with just one 3 core flexible cable, especially as you wont be using both lights at the same time
 
Is the three-core wire ordinary shore mains cable? Blue, brown, and yellow/green? Perhaps someone just used what they had to hand (or what was cheap) instead of proper two-core tinned marine cable. If so, perhaps the third core isn't connected to anything? Do the lights come on when you connect the ones you've identified as positive and negative?

Pete
 
May well be for an old long since removed shore power system. there is an old orange cable in place at the back of the boat not connected to anything. TBH not sure why there are three wires in each cable. So will it work if I just connect the Positive and negative and tape off the neutral/ground
Was gonna bring the mast down to add lazy jacks sail pack Furling genoa and put and LED tricolor on but really want to get the boat launched now so probably gonna leave that a coupla months and do t over winter llayup
 
I think that you may just have 3 core cable being used but as mentioned on two cores being required. We get hung up in the colours and normal us but remember they are wires for electrical connections with colours to speed things up, most of my cabling is black multicore with numbers on each core, means less cable runs and it's free as I've been given a few drums
 
thesaintlyone said:
May well be for an old long since removed shore power system. there is an old orange cable in place at the back of the boat not connected to anything. TBH not sure why there are three wires in each cable. So will it work if I just connect the Positive and negative and tape off the neutral/ground
Was gonna bring the mast down to add lazy jacks sail pack Furling genoa and put and LED tricolor on but really want to get the boat launched now so probably gonna leave that a coupla months and do t over winter llayup
Click to expand...
you need to identify which cores in each cable are actually connected to the lights.
You can do this with a multimeter on it's lowest ohms range and then confirm by connection to a 12 volt supply.
Tape off the unused cores.

Sounds as said above that it has been wired with 3 core domestic flex rather than properly with tinned twin flex
 
I suspect Oldhairy has the rights of it

Assuming you have the usual masthead tricolour and anchor light and lower down the mast a combi steaming and deck light, one three core cable will go to the masthead lights and the other to the lower light

Each cable will have a common neutral and the live feed to each of the lamps

So one cable will be neutral - tricolour feed - anchor feed and the other will be neutral - steaming light feed - deck light feed

That's what I would expect to see anyway

Given the rather obvious confusion, might I respectfully suggest consulting with somebody familiar with boat electrics (not necessarily a professional, we tend to ask for money :o tap up a knowledgeable friend or fellow sailor for a bit of on board advice. Beer often works :D )
 
thesaintlyone said:
Yes it could well be. TBH if I can just ignore the third wire then that is probably what I will do till I sort everything out properly over winter lay up
Click to expand...

If you don't plan sailing at night until after the winter, just ignore them and sort out when you have the mast down. much easier to see what is going on then, and you will probably want to rewire the mast anyway. Even if you do need nav lights, presumably you have deck level lights as well.
 
On the two boats that I have owned there have been 3 wires to the Masthead lamp.

One the supply to the Tricolour.
One the supply to the anchor lamp that is built in.
The last one is the return/earth.
 
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Oh I appear to have misread the thread title, I thought it said what to do with the extra wife and I was just going to offer my commiserations.
 
prv said:
Yes, if the "positive" and "negative" are connected to either side of the bulb at the masthead. Otherwise, no. We can't tell from here.

Pete
Click to expand...
On both my Benes the mast lights were fed by what looked like house hold 3 core. They used two positives and a common negative.
Stu
 
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