Egadz! The electrical system!

[My Mistress]

I forget who described a used Macgregor's electrical system as a "rat's nest", but I think I found it in my boat!



I'm not scratching my head as much as pulling out hair! I was wondering why the AM/FM radio wasn't working....well, it was never connected to power. In fact, the thin wire used to guide electrical cables through narrow places is still attached to it. The rest is a myriad of wires connected to power buses and switches. The picture is of the space above the galley. Most of the foam has been pulled out.


This is a shot of the area under the galley. I think I have no less than 10 of those power strips throughout the boat. In some circuits, ordinary household wire was used. I'm looking at simplifying the systems to one or two main power strips, located where they can be easily accessed.

Another issue I found was when I pulled the batteries. They were wired negative to negative, while the wiring on the positive poles went in opposite directions to where-ever ( I haven't tracked everything down yet).
This seems like a half of a parallel installation, vs two separate battery systems to me. I may be wrong though.

It sure is a pain in the rear trying to duck my head upside down in all those compartments while my glasses fall upward, off of my nose to my forehead.......

OK, after all that, what would be wrong with wiring the batteries together in parallel vs the current dual battery system?

[FlyboyTR]

At least you have a few buss bars and some fuses...you're in better shape than me! LOL. I'm finding wire nuts and wire twisted together and wrapped with duct tape...laying in the water.

I also found very little foam in the overhead compartment above the sink. I packed the area with 1 & 2 liter drink bottles; non conductive, lightweight, buoyant and will not absorb moisture. I did throw them in the freezer for about an hour, with the tops loose. Pull them out and quickly secure the tops. That way, cool air won't cause the bottles to collapse when cold.

Good luck with your rats nest!

[My Mistress]

Does anyone know of a basic wiring schematic for Mac 26's?
I'd really like to simplify everything.

[Stevenhigbee]

I bought my boat from an electrician, who labeled every connection, and made a wiring schematic. But I'm away from where the boat is until mid-January. When I get back, I could scan the schematic.

[81venture]

I had a similar issue when I bought my

Nothing inside worked, rotten switch panels, lamp cord...etc.

I gutted it. Literally stripped every wire out of her and just started from scratch..

In the end, you will most likely find it easier to do so than to try and figure out a rats nest of hodge podge

I would start by pulling and cutting everything out...go through the pile and see what you can salvage (battery switch, ground block, switch panels, etc) and then use the old wires to pull in new. If the runs say from your central distribution location to the front of the boat are good quality go ahead and re-use to avoid the Pain of pulling new lines where you don't have to

but yeah, just stat over and do it right... there is no "schematic" that i am aware of....in my boat is all in my head

I run
2 batteries,
Shore power
Billy box with A/C unit
GPS, lights, cabin lights etc
2 motors the 50, and an 8hp tohatsu kicker, both charge batteries if running

[Tomfoolery]

Assuming the Classic was wired similar to the X, there were only 3 OEM circuits. 1) Navigation lights, which included sidelights (a single bi-color bow light in the case of the trailer Macs), plus a stern light, with the leads landed on the same fused switch, 2) Masthead (steaming) light, and 3) cabin light(s). Grounds were combined onto a screw that was just floating there (!), and the hots all came from the little fused switch panel. That was it. Oh, and the OB, but since that was dealer installed, it wasn't wired at the factory.

[My Mistress]

I should have searched this site a bit more. I found what I was looking for in the Powersail section:



I have a 6-gang panel that I would like to keep vs the simpler 3-gang panel, so this schematic looks like it will do the job.

81Venture - a neighbor suggested that, but it's a whole new world to me. I think I'm going to do it one circuit at a time since they all seemed to function.

[Interim]

I'm rewiring mine this winter too. My understanding is that lamp cord was OEM, because it is water proof but not water/fuel proof. I'm not sure that makes it ABYC. Those of you who have re-wired, do you use marine grade wire or stick with lamp cord?

My batteries were in parallel too, but I don't understand the need to connect the negatives. On my boat, one battery is for the outboard and the other for house power.

--john

[FlyboyTR]

I'm rewiring mine this winter too. My understanding is that lamp cord was OEM, because it is water proof but not water/fuel proof. I'm not sure that makes it ABYC. Those of you who have re-wired, do you use marine grade wire or stick with lamp cord?

My batteries were in parallel too, but I don't understand the need to connect the negatives. On my boat, one battery is for the outboard and the other for house power.

--john

I plan to replace everything that may come into contact with water within the hull...or anything that looks suspect. Once I get into it, I may just replace everything!

Having the two negatives connected together is useless unless there is a switch or relay to tie them together for charging purposes.

[grady]

I'm rewiring mine this winter too. My understanding is that lamp cord was OEM, because it is water proof but not water/fuel proof. I'm not sure that makes it ABYC. Those of you who have re-wired, do you use marine grade wire or stick with lamp cord?

My batteries were in parallel too, but I don't understand the need to connect the negatives. On my boat, one battery is for the outboard and the other for house power.

--john

No lamp cord!!!!!! Use good marine wire!!!!! Or good quality wire. All the smaller wire I used was MIL Spec aviation wire just because I have access to it. Try not to use crimp splices or connectors those will corrode after time and cause you issues. Solder and heat shrink or use enviromental splices.

You will need to conect the negatives if you want to cross charge or use. If you have two complete seperate electrical systems no need to connect the negatives.

[Sumner]

...No lamp cord!!!!!! Use good marine wire!!!!!

Just ordered $300+ today from here...

https://www.genuinedealz.com/

... for 22 toggle switches 10 long terminal strips 100' of #16 red and blk wire, hear shrink and other items for the master switch panel for the Endeavour and for a secondary switch panel that will replace the one on the boat...



.....but keeping it as I think it looks cool although you can't see it anymore since it is...


http://purplesagetradingpost.com/sumner ... index.html

http://purplesagetradingpost.com/sumner ... index.html

...behind the companionway storage. The new switch panels will be by the Nav. Station. I've used
genuinedealz.com for 90% of my other wiring needs as the pricing is good and they ship right out,

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links

[FlyboyTR]

As an FYI... Several years ago, I purchased a 250' roll of 16/2 tinned marine wire for $15 at a yard sale. Yep...it was the deal of the day! So all my boat electric upgrades uses the same wire (white sheath with red an black coated wires). It can really be confusing. So...When doing electrical work where I will have multiple wire sets that all look the same, I use some cheap white heat shrink for labeling. I use a fine point permanent marker and write what the wire goes to or from. I label both ends of the wire set. I usually flatten the heat shrink tubing and write the ID on both sides, allow it to dry and slip it over the wire. I then heat shrink it just enough to keep it from sliding. Flame or heat gun...doesn't seem to degrade the ink.

It sure make finding the wire you need much easier in the future.

[81venture]

I use leftover wire from my old security business..

I have rolls of good quality 14/4 that is perfect.

My shore power I confess I used Romex house wiring, but with the way I wired the locations of the breaker and 2 outlets the runs are extremely short. I think maybe 10 ft total....

Figured since they were not long runs I could get away with it

[Interim]

Is there such a thing as "over building" wiring? I understand that wire which is too small will produce heat. Does larger wire have greater resistance? Other problems?

My house circuit will just be powering running and mast lights. No accessories installed at this point.

--john

[Tomfoolery]

Solid copper doesn't flex, and neither do buildings, at least not that you'd notice without measuring equipment. Boats do, however. And they vibrate or shake, both from the engine, and from pounding over waves. And trailering. So stranded is used. And even then, it should be well supported, as marine wire is not as finely stranded as cord (like SO cord, or lamp cord, for example, which is specifically designed to flex repeatedly). I'm not suggesting lamp cord over marine wiring; just pointing out that best-practice is best for a reason.

The only downside I see to 'oversized' wiring is in terminations, which can be problematic if the device or fixture isn't designed for it (and adding a smaller pigtail makes for another failure point). DC resistance goes down with increase in cross-section (lower gauge number), all other things being equal. Going too small, on the other hand, can make for delicate conductors, even if the load (like LED lighting) doesn't require 'normal' sized wiring. And you don't want to put tiny wire on a circuit with a fuse or breaker larger than recommended for that gauge.

I would think mechanical protection ranks very high on the list of priorities, as a spare anchor slamming into some hidden conductors during a knockdown or whatever can ruin your day, especially if it ends up in fire. I would imagine most or at least a large proportion of boat fires are traceable to electrical problems. But that's just me talking through my hat.