Battery to Fuse panel routing? Fuse values?

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tegwilym
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Battery to Fuse panel routing? Fuse values?

Post by tegwilym » Wed Apr 14, 2021 6:22 pm

I apologize if there is the answer somewhere in here, but didn't find it when searching. We just got a 2005 26M recently (3rd owners) and we have been going through it cleaning, testing and replacing things.
Testing the electrical, there was no power to the fuse / switch panel. Clipping a battery charger on the bus behind the panel, I was able to test things out (lights, stereo...etc).
We have 2 batteries with the typical 1, 2, both, off switch but no connection to the fuse panel. I understand there should be a fuse between battery and the panel, but haven't found it yet, and unsure where the power cable runs. I was able to feel 4 or 5 cables running down the port side behind the panels, but tracing the main is hard since everything behind the panel is very tight.
So my first question: Does anyone have an idea where the main power connects? It goes to the back of the boat somewhere, but seems it's under the ceiling panel/cockpit floor. I'm temped to just connect directly to the battery, but if it's just a simple fuse or connection that would be best. I just can't seem to find it.
Also, I blew 2 fuses - a 6A to lights (polarized backward for LED swap) and a 5 amp to Instruments. I'd guess instruments would be better with a higher rating and their own inline fused wire. Lights maybe a 20 amp since it seems our stereo (which has a 15 amp fuse already in it). Did these boats originally have low amp fuses or could this be a previous owner fix?

Thanks,
Tom

I did see this diagram, thanks to whoever posted it, this is how mine is pretty much hooked up from what I can see.
Image

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Starscream
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Re: Battery to Fuse panel routing? Fuse values?

Post by Starscream » Thu Apr 15, 2021 3:38 am

I can't answer for the M, but for the X there was no protection for the wiring between the battery and the main panel. Even worse, the wire was the lightest, cheapest crap-wire ever to see the inside of a boat.

We now have two fuse panels on the boat, one on either side and both fed with 10-gauge marine wire. One is protected with a 30A breaker and the other with a 20A in-line fuse, both located just downstream of the battery selector.

Some owners have added protection right at the battery terminals but I forget if they used a breaker or a fuse. There is some sort of built-in device that mounts right on the terminal, IIRC. I'm sure someone will post it.

It really is best to bite the bullet and do the whole thing over. I understand what Roger was trying to do with these boats, but I sometimes think he got it wrong. Putting in real wire probably wouldn't have cost more than $50 extra per boat. OTOH tens of thousands of boats built, zero wiring fires (as far as I know).

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Be Free
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Re: Battery to Fuse panel routing? Fuse values?

Post by Be Free » Thu Apr 15, 2021 7:43 am

I'd love to hear from some :macm: owners on this. Why would the connection between the battery and the fuse panel run to the back of the boat? Isn't it a clear run from the battery to the fuse panel going under the stern berth and between the liner and the hull?
Bill
2001 26X Simple Interest
Honda BF40D

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Russ
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Re: Battery to Fuse panel routing? Fuse values?

Post by Russ » Thu Apr 15, 2021 8:55 am

I used one of these terminal fuses for the main. I redid much of the wiring as factory was a bit sketchy. (single bolt for a common). Polarity was not a consideration. Earlier boats had lamp wire instead of proper marine grade. Stock panel was a junky 4 switch/fuse deal. I broke it figuring out how to remove the fuses.

If it's stock, seriously consider redoing much of it and maybe even a new panel.

--Russ

tegwilym
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Re: Battery to Fuse panel routing? Fuse values?

Post by tegwilym » Thu Apr 15, 2021 9:48 am

Thanks for the replies. Yes, the main power connection _somewhere_ in the back of the boat really has me stumped where it's located. I simply want to make sure that is connected to power up the lights and everything on that panel. I did notice the polarity issue also, this all started when I was trying to swap out all the light bulbs with LED. Nothing worked - obviously backwards. I pulled down one of the fixtures and sure enough, the black ground was going to the center contact on the bulb. So I need to get my fingers in there and swap that mess somehow.
I did notice that single common ground bolt behind the panel. That's just foolish, why not simply put a ground bus terminal in there? The wires seem cut so short that there isn't much to work with either.
The only cables connecting to my batteries are the large current cables that run to the back of the boat, engine, and from there...???

Ugh! I just want to hook it up so it works, then worry about re-doing the whole mess in the fall.

Tom

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Re: Battery to Fuse panel routing? Fuse values?

Post by C Buchs » Thu Apr 15, 2021 11:20 am

I have an :macx: , so a lot of it is at least a little different.

I want to upgrade my anchor light and steaming light so that I don't have to go up on deck to change the plugs that I have to coat in dielectric grease and wiggle to make work. I bought this switch https://www.amazon.com/gp/product/B07MV ... UTF8&psc=1 that I'll have to cut the panel a little to make work and plan to use the method Russ described on Feb 23, 2018, in this thread http://www.macgregorsailors.com/forum/v ... =8&t=26638. I highly recommend reading that whole thread. There are lots of nuggets in there.

Like Russ, I also broke one of my fuse holders and I have a switch that I sometimes have to wiggle to turn my cabin lights on. I need to replace the whole thing, but it's not going to happen this year. So I was going to buy a couple of replacement fuse holders and a couple of extra switches. They're less than $10 each, but I found the whole panel for $24 here https://www.amazon.com/gp/product/B000Y ... UTF8&psc=1. So now I have lots of spares to keep me from fixing it right.

Jeff

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Re: Battery to Fuse panel routing? Fuse values?

Post by Starscream » Thu Apr 15, 2021 11:54 am

Be Free wrote:
Thu Apr 15, 2021 7:43 am
I'd love to hear from some :macm: owners on this. Why would the connection between the battery and the fuse panel run to the back of the boat? Isn't it a clear run from the battery to the fuse panel going under the stern berth and between the liner and the hull?
I wonder if it really does just run straight up from the battery the fuse panel, but you may just not see/recognize the wire? The "main" power wire is a very, very, light lamp cord and you may not even recognize it as the actual main power wire.

This is a photo of the "main" power wire in the X, overlaid overtop of the new main power wire that I just installed.
Image

There's no way I would have recognized this as the "main" power wire if I found it running through a compartment somewhere.
Russ wrote:
Thu Apr 15, 2021 8:55 am
I used one of these terminal fuses for the main. I redid much of the wiring as factory was a bit sketchy. (single bolt for a common). Polarity was not a consideration. Earlier boats had lamp wire instead of proper marine grade. Stock panel was a junky 4 switch/fuse deal. I broke it figuring out how to remove the fuses.

If it's stock, seriously consider redoing much of it and maybe even a new panel.

Right, that's the thingy I was talking about. Makes a lot of sense to fuse the main power wire right at the battery. My system is only fused after the battery selector so there are a few feet of unprotected wire in my system.

tegwilym
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Re: Battery to Fuse panel routing? Fuse values?

Post by tegwilym » Thu Apr 15, 2021 12:19 pm

I wish I knew where the main power splits off from the big cable to the engine when it leads to the back of the boat. I only see the 5 "house wires" going down the port side then it feels like they go under the ceiling panel and vanish. *Ugh!*
The wiring of the boat is so simple, but the way they ran things is just confusing.

Tom

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Re: Battery to Fuse panel routing? Fuse values?

Post by Starscream » Thu Apr 15, 2021 12:43 pm

C Buchs wrote:
Thu Apr 15, 2021 11:20 am


I want to upgrade my anchor light and steaming light so that I don't have to go up on deck to change the plugs that I have to coat in dielectric grease and wiggle to make work.
Quick question Jeff: I thought dielectric grease was non-conducting and if you coat a connector with it, it will be very hard to make contact. My primitive understanding is that you are supposed coat a pre-made permanent connection with dielectric grease to protect the connection from corrosion, but you don't use it on a quick connect connection?

C Buchs
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Re: Battery to Fuse panel routing? Fuse values?

Post by C Buchs » Thu Apr 15, 2021 12:58 pm

Starscream wrote:
Thu Apr 15, 2021 12:43 pm
C Buchs wrote:
Thu Apr 15, 2021 11:20 am


I want to upgrade my anchor light and steaming light so that I don't have to go up on deck to change the plugs that I have to coat in dielectric grease and wiggle to make work.
Quick question Jeff: I thought dielectric grease was non-conducting and if you coat a connector with it, it will be very hard to make contact. My primitive understanding is that you are supposed coat a pre-made permanent connection with dielectric grease to protect the connection from corrosion, but you don't use it on a quick connect connection?
I looked it up and YOU'RE RIGHT!!! I learn something new every day. Maybe that's part of the reason it doesn't work. Thanks!

Jeff

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Re: Battery to Fuse panel routing? Fuse values?

Post by Starscream » Thu Apr 15, 2021 1:51 pm

tegwilym wrote:
Thu Apr 15, 2021 12:19 pm
I wish I knew where the main power splits off from the big cable to the engine when it leads to the back of the boat. I only see the 5 "house wires" going down the port side then it feels like they go under the ceiling panel and vanish. *Ugh!*
The wiring of the boat is so simple, but the way they ran things is just confusing.

Tom
I really don't think it splits off from the motor cables. Are you sure there isn't a small wire sneaking out of the battery selector switch? It would look like a "house wire" of remarkably light construction.

Jeff...lol, I seem to find everything out the hard way, so you made me feel a bit better.

tegwilym
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Re: Battery to Fuse panel routing? Fuse values?

Post by tegwilym » Thu Apr 15, 2021 6:15 pm

I assumed there would be something off the switch near the battery, but there is nothing there. If I designed the boat that's where I would put it. Why have the main power connect....somewhere in the back?
I spent more time looking today and got nowhere. This and the backwards polarity of the interior lights is really annoying too and they are all connected with wire nuts and shoved in the small hole. I'm just getting -really- annoyed with how this boat is put together. Don't get me started on the two bolts holding the gas filter on the rear part of the transom step, that's another gripe.

Tom
wiring.jpg

I really don't think it splits off from the motor cables. Are you sure there isn't a small wire sneaking out of the battery selector switch? It would look like a "house wire" of remarkably light construction.

Jeff...lol, I seem to find everything out the hard way, so you made me feel a bit better.
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Be Free
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Re: Battery to Fuse panel routing? Fuse values?

Post by Be Free » Thu Apr 15, 2021 7:01 pm

You mention a switch near the battery. I did not see it in your diagram. What does it do?

The wiring in your picture looks significantly better than the original wiring for the boat. Everything came from the factory wired with 18AWG lamp cord.
Bill
2001 26X Simple Interest
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Russ
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Re: Battery to Fuse panel routing? Fuse values?

Post by Russ » Fri Apr 16, 2021 7:16 am

tegwilym wrote:
Thu Apr 15, 2021 6:15 pm
I assumed there would be something off the switch near the battery, but there is nothing there. If I designed the boat that's where I would put it.
My understanding is you have no power to the main panel, right?
No wire going to where you would expect, the main A/B/Both switch?

I rewired everything including a new main run to the panel. I ran it under the aft berth and then up the headliner to the panel. I don't remember where the original main power ran from.

At this point, you can see the PO did some things to your boat that are not stock. Must have also lost the panel 12v DC main supply. Pretty sure OEM had no wire nuts, just crimp connectors. No fuel filters. Heck, didn't have a motor. That was a dealer add on.

I'm assuming you didn't find the 12v ground either. I would go buy some marine grade wire and run it to the panel like I did, under the aft berth then up the side of the headliner to the panel. Fuse it at the main switch and put rewiring on a project list for later.

If you really want to play detective, you could try to trace the 12v panel source back. But it sounds like the PO did some funky stuff and may lead to nowhere.
--Russ

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Re: Battery to Fuse panel routing? Fuse values?

Post by Russ » Fri Apr 16, 2021 7:22 am

C Buchs wrote:
Thu Apr 15, 2021 11:20 am
Like Russ, I also broke one of my fuse holders and I have a switch
I learned AFTER that the fuses come out easily if you push something pointy into the SIDE of the holder. Seems like a stupid design for a fuse holder that you need a "tool" to remove them. The whole seadog stock fuse panel seems junky. $24 for a marine part is cheap.

For connectors (like trailer wire connectors), I use this stuff.

--Russ

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