Rewire the Mast

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Curwen
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Sailboat: MacGregor 26D
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Rewire the Mast

Post by Curwen »

Hello,

I have an 89 26D that needs to mast rewired. The lamp cord that was used has lived past the expected life cycle. I am not getting enough power at the lights to power anything.

While rewiring, I want to add an anchor light to the top of the mast. My questions are:

What gauge wire to use? I have replaced the steaming light with an LED light and the anchor light is also an LED. I planned on using 14 gauge wire. I estimate that my mast is 32' feet long so that should be plenty of gauge for that distance and load. Is that the right gauge of wiring?

The 26D has three switches on the fuse box, one for house lights, one for navigation lights, and one for the mast. How to wire the anchor light? I can do two runs of 14/2 and switch out the plugs on the deck and just use the existing switch. Another option would be to replace the deck plug with a 4 way plug and replace the fuse box with a 4 switch fuse box. I know there is an option with a 14/3 wire and a rocker switch, but I think that would also require replacing the fuse box.

Any secrets to removing the mast cap? I assume you can drill the rivets out and re-rivet when the wiring is replaced?

Any special tips pulling the wires? I planned on tying string to the old wires as I pull them out and use them to snake the new wires back.

Is there any insulation or anything else inside the mast to be worried about when doing this work? I have read about people stuffing pool noodles inside the mast to quiet slapping, but not sure if that is a problem on the 26D since I don't hear my wiring slap.

Thank you for any and all advice,

Curwen
chipveres
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Re: Rewire the Mast

Post by chipveres »

Your 14 gauge wire is ample. 16 would also work. No smaller than that just for ruggedness, not because of the tiny current. There is no telling what is inside the mast without looking. Some people, confronted with a mast full of dodgy foam, have driven 1/2 inch thinwall electrical conduit through it to make a hole. I like the idea of using two plugs at the mast base due to its simplicity, but you can make the wiring as simple or complex as you like.

Chip V.
s/v Sand Dollar
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Russ
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Re: Rewire the Mast

Post by Russ »

The LEDs consume VERY little power. As mentioned above, the main consideration will the wire support its verticle weight. Also consider using wire ties to keep it from slapping back and forth as the boat rocks.

Since you are using LEDs which most require correct polarity, you can use the same 2 wire deck fitting and reverse the polarity at the switch. This is what I did and it works very well. Legally, you can only have one illuminated at a time.
I used the breaker switch for "mast light" and then a DPDT toggle switch to flip between steaming light and anchor light.

Here's a link to how to wire it.
https://macgregorsailors.com/mods/index ... item&id=16

BTW, my LED fixtures were not polarity dependent, so I had to actually place an actual Diode in-line. Much easier than running more wires.
--Russ
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1st Sail
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Re: Rewire the Mast

Post by 1st Sail »

I ran separate wires for each light to the cabin top. BWY sells a 4 pole stainless thru hull connector. Connected both to a double throw double pole switch. Anchor light 'up', off (power), running mast head light 'down'. I used the existing power wire to the mast head light connected to the power in poles of the switch. You can wire the bulbs parallel with the bulb inserted reverse polarity and then use diode(s) and double pole switch to reverse the polarity on a single wire. With the 4 pole connector I just ran two wires and done.
:macm:
Interim
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Re: Rewire the Mast

Post by Interim »

Regarding supporting the weight of the wire, I just attached a zip tie at the top to bear the weight so it wouldn't be hanging on the connections.

--john
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Democritus
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Sailboat: MacGregor 26X
Location: Santa Rosa, CA

Re: Rewire the Mast

Post by Democritus »

For those who rewired from the deck to the switch panel, were you able to pull the wire all the way through from either the deck to panel or vice-versa, or did you have to pull the wire out through access holes?
Vince
"Spiraling Shape" 2002 26X
Tohatsu MFS50A
K9Kampers
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Re: Rewire the Mast

Post by K9Kampers »

When I rewired from the mast deck plug to the switch panel, I used all the access holes to pull the wires along as the route is not a direct path. I even had to drill a new 2" access hole in the cabin liner in the vicinity of the port chain plate to discover that the factory wires were sandwiched between the chain plate and the hull.
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