Electrical tear down 79 s&s swan

I will be installing a new mastervolt charging and inverter system into a 1979 s&s swan 57'. I am currently in the process of understanding the inner workings of this 38 year old boat and what needs to stay and what needs to go. The current set up is diesel generator220vac/diesel engine alternator24vdc for direct 24vdc use/battery charger for the 24v bank. The bank is 8 12v series parallel lead acid batteries that will be getting replaced with agm batteries of similar output.Is there any one here with knowledge on the operation of old systems and electronics that have simply become outdated or replaced with more efficient devices? I am an electrician by trade but have never worked on marine application. The hardest part is not being able to see the current set up as it is buried throughout the boat. I have schematics and wiring diagrams to assist but years of "do it yourself" wiring seems to plague this boat. Essentially any tips or ideas on thought processes and troubleshooting ideas would be greatly appreciated.

 

I did a restoration (all the way down to replacing engine beds and stringers) on a 1973 Silverton 25' back in 2007-2014. Of course my boat is much smaller and based on a 120 vac / 12vdc set up. Of all the work I did on this old boat, I enjoyed designing and building my electrical system the most. Sadly, on most of the recreational marine websites, there doesn't seem to be a lot of interest in DIY electrical system design and installation. I think this is a shame as in my opinion, having a reliable, flexible and robust ac/dc system makes my time aboard much, much more comfortable. Since you are an electrician, you have a huge head start as you already know the language of electrical engineering. You're probably going to end up removing just about all of the DIY, previously installed electrical components. In my boat, the only original electrical component that still exists is the engine wiring harness that ran from the upper and lower helms. This was essentially "plug and play". When I started, I thought I could salvage at least part of the house system but as I got deeper into the project I realized that I wasn't going to be comfortable with 30+ year old wiring that was poorly installed anyway so I removed the entire house system and started from scratch. I found almost all of the wiring to be substandard. No tinned copper, stiff cracked wire insulation, cheap poly connectors and of course the "birds nest". I won't even talk about the grounds and bonding that I saw. It's a wonder someone wasn't killed. It took quite some time and many thousands of dollars but I now have a new electrical system in my 45 year old boat. Done right and done personally.

I used the following book and found it very helpful as I laid out the new system, first on paper and then in the boat. I keep it on my boat as a reference.
https://www.amazon.com/Boatowners-Mechanical-Electrical-Manual-Essential/dp/0071432388

I looked up your boat and it looks like it's well made. You'll need to evaluate the original equipment wiring as well as the DIY add on's. In five minutes I found this boat (link below) that had been refitted. Perhaps you could do some posting on a Swan specific website and see what others have done. It's inspiration anyway. If you plan on keeping the boat just go through it. It will cost you a bit and there is certainly some work involved but when you're out there and you know your electrical system is reliable, the peace of mind is priceless.

S&S Swan Association https://www.classicswan.org/restorations_photos.php?codice=41

Here's a link to an article from a few years ago in Professional Boat Builder. Some good thoughts.

Professional BoatBuilder - 134 - Dec-Jan 2012 https://pbbackissues.advanced-pub.com/?issueID=134&pageID=57

Good luck with your boat, she's a beauty! Welcome to the forum as well.

MIA

 

Thank you for the reply! Your thoughts are exactly mine. I'm even more tempted to start fresh because it's not my boat it is a friends and he will be doing 2 -3 Atlantic crossings per year. Here's a couple pics of the "brains". It's quite overwhelming lol. I'll will check out those links as well!

 

I can see you're already labeling things in there. Kept a log of everything I took apart. Shot plenty of photos and even some video as I pulled things apart. Laid everything out on paper before I started buying supplies and components. Shop around. Here in the States there are large differences in prices for identical parts. If you're patient you can save a lot of money.

Good luck,

MIA

 

I did a total refit on a 1974 Swan 44 and worked on a number of Swans some years ago.
Don't tear out the any wiring yet. You're going find that the majority of it is fine, and running wires in any boat (but Swans especially) is a huge pain.
Best to try to identify the factory wire bundle from what's been added later and can usually be done by color code, id number tags, wire tie level, etc.
A Tone and Probe wire run tracer saves time to i.d. the unknown wires.
Remove or mark wires not needed, (old stereo(s), tv, LORAN, etc.)

Check out ABYC sect. E for electrical guidelines and info.

If the owner plans to cross the Atlantic often what about Europe vs U.S. voltage differences for the shore power input.