Boat Rewire

[SailerMatt]

Hello! I've got a 1975 Cal 2-27 that I am going to rewire. I have all the parts and will start Saturday. My bug question is is it wiser to replace one system at a time, or just rip everything out and start over? Right now, it is a complete rats nest with lots of ghost wires.

I am building my own panel, with a toggle switch for everything, a volt meter, two battery switches (on/off only) for two banks and a emergency connector switch. That along with inverter power switch and smart charger, it will be on a piece of zinc plated steel from Home Depot. $4 and my dad's tool shop.

I will post up a wiring diagram of what I'm expecting to do and I'll take pictures along the way!

Any advice would be great! And experiences or stories that you want to share as well!

I am also replacing the plumbing, which includes two sinks, a shower, a head and an additional washout station for the anchor.

Thanks for reading!

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[FlyingCloud1937]

RIP IT, anytime spent on trying to figger out the existing, will be a complete waste.

Now, that being said.

You must develop a schematic of all of the circuits needed.

Start with the Primary...ie bats an bus load cables, and any large loads circuits.

Then the Engine Branch circuits,

Then the house/lights pumps, and creature comforts...maybe even the an inverter.

Now is the time to add the various of the AC circuits into the design...chargers, Domestic HW, AirCon. ect.

Lloyd

Originally Posted by SailerMatt

Hello! I've got a 1975 Cal 2-27 that I am going to rewire. I have all the parts and will start Saturday. My bug question is is it wiser to replace one system at a time, or just rip everything out and start over? Right now, it is a complete rats nest with lots of ghost wires.

I am building my own panel, with a toggle switch for everything, a volt meter, two battery switches (on/off only) for two banks and a emergency connector switch. That along with inverter power switch and smart charger, it will be on a piece of zinc plated steel from Home Depot. $4 and my dad's tool shop.

I will post up a wiring diagram of what I'm expecting to do and I'll take pictures along the way!

Any advice would be great! And experiences or stories that you want to share as well!

I am also replacing the plumbing, which includes two sinks, a shower, a head and an additional washout station for the anchor.

Thanks for reading!

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[knottybuoyz]

When you yank out the old wiring pull in some new fish lines at the same time. Leave yourself a few extra. I use the bright pink surveyors line. Easy to see & tough!

When you put your panel together pay extra special attention to the spacing on the back. The switches usually take up more room on the backside than they do on the front.

Label every run!

[Ex-Calif]

I am on the same journey Matt.

I tentatively advise to rip it all out and start fresh but you should document every circuit you have first, then use a tool to create a schematic. I found a free tool and have a working schematic now.

It's a good time to spend the extra bucks and do proper fusing, distribution panels and proper wire & crimps.

[Pelagic]

Hi Dan. What schematic tool did you end up using?

I am redoing mine also and have just hand drawn for now

[Ex-Calif]

I ended up using expresssch...

All the tools I looked at had a "limited" number of objects. I have managed to make a few custom ones for my schematic. If you decide to use expresssch PM me an email address and I will send you the library of objects I have created - switch panels, various gauges, alternator, starter, BMV602, ACR, solar panels etc.

Attached is my schematic - work in progress. While the tool didn't save tons of time the first go around, revisions and modifications are much faster.

I found changing the grid layout to 1mm allowed a high level of precision in laying out runs and stuff.

[Rustic Charm]

I purchased my boat not quite three years, 2012 I rewired the inside, and last year I took down the main mast and retired that.

If your wiring is a mess of spaghetti with old non marine wire, just rip it out and start from scratch. It will save you a hell of a lot of time.

Definitely draw yourself a schematic. I did mine with colour pens. Lots of advice from CF members.

Only use 'tinned' marine wire. Don't let anyone convince you otherwise and frankly it doesn't add much to the cost anyway. I made my own panel as well. My cabinette is on hinges so it opens easily so I can get to the inside.

Research using an ACR for your charging and I'd recommend a house/reserve system rather than a house/engine set up. This will make a difference to how you set up your main control switch.

And my last suggestion is 'tagging' or 'labeling' cables. I really recommend what I discovered. Purchase a $27 label maker, small size tape and clear plastic heat shrink. Make a point of labeling everything and then put a clear heat shrink over the label. Do this on both ends of the cable run. It's cheap, effective and looks good.

Maybe this is my last one. Change all lighting except the steaming light to LED.

Hope that helps.

[Pelagic]

Thanks Dan,
I will download and play with it this weekend

[Garrettw]

Unless you need your boat's electrical system to stay partially functional during the install, the best plan, by a long shot, is typically to take it all out and start fresh, as others have said.

[a64pilot]

If you don't rip it all out, you will still have a mess, I'll bet you find a significant number of wires that don't go anywhere. People seem to add wire as needed, but don't seem to remove wire, just too hard I guess.
I've had real good luck using SS leader wire as fishing wires too, might consider running PVC pipe as "conduit" too

[nautical62]

I rewired and re-plumbed two boats I owned with the exception that on the second one I reused the existing anchor light and steaming light wires which were functioning and hard to replace - So those I labeled and left in place.

Using existing wires to pull new one's through either directly via a intermediate line as mentioned earlier is also something to think about.

I found a basic schematic helped, but did not feel a need to trace every single wire on a schematic. I found using a bus bar very helpful for the many cabin lights, fans, etc.

[leftbrainstuff]

Ripping all wiring out is a last resort but sounds like it might be your best option.

Rather than use galv steel, which has no place on a boat, consider using a suitable engineering plastic or aluminum for your panel. Much nicer to work with and no corrosion to worry about.

Make sure your wiring diagram is sorted before you start. Allow for adding wiring for future needs with space in your trench or pipe runs.

Are you using ABYC colors? If not then labe using a waterproof option at each end before you chase each wire.

Sent from my GT-I9300 using Cruisers Sailing Forum mobile app

[knottybuoyz]

I made my panel using frontpanelexpress.com



It is an expensive choice though. The panel without the switches, breakers, meters etc. cost $185.00

You can still use their free software to design your panel. Print it out full size and use it as a template to cut your own.

My wiring diag has each circuit numbered. Each number gets put on each wire with the 3M wire markers. See attached.

[IdoraKeeper]

SailorMatt, you have a great project going. Your getting good input on this thread. It will be a lot of work but if done correctly you will not need to do it again as long as you own the boat. In the end you will have an excellent one person live aboard and day sailer. If done right, when it comes time to sell, a smart buyer will be delighted to have it.

[Roy M]

I use a slightly different approach before anything else. I use an Excel spreadsheet to design my system. I start with where the juice originates, at the batteries. I give this source wiring (Primary) a numerical code of 00 as a prefix. Example, 00-01 is the house bank positive primary. The ground wires get a prefix of 99, example, 99-01 is the ground from the engine block to the negative buss bar.

Then, I write down all of the different circuits I want to have in the boat, with a few extras for future stuff. Each circuit gets a prefix code, example, starboard cabin lighting is 01. Then, I begin to figure what electrical units will be powered by each numbered circuit breaker. When I have this list complete, I examine how I will supply that component with juice. Some wires go forward, others aft or elsewhere. To reduce clutter and make circuits sized correctly, I distribute the juice coming from the circuit breaker to a dual buss bar of 5 or 10 screws. The wire from the breaker is sized (using Blue Seas calculator tool) to meet the entire current load required by everything being supplied by that breaker, as if everything were being powered simultaneously. Then, individual two-wire (duplex) cables, sized for the appropriate current, go either to a secondary distribution buss or an isolated device using the juice. Result, fewer wires clogging up routes, and easier trouble shooting or modification in the future. Then I apply the code to each of the distribution wires, and then the individual units. Example, 01-03-02 is my code for the wire feeding the galley stove area overhead lamp. From the distribution buss a duplex #10 cable goes aft to the galley overhead distribution buss, from which several other devices are fed their juice (lights, fans, etc.). Every wire has a code and a label at each end. Having precalculated the current demands, and determining the route of the distribution circuit, I can then find the best wire size to meet my needs. All of this is done on the spreadsheet before pulling the first wire. Since every wire is also now coded, you can print out the section of the spreadsheet that you will be working with on any day (because it's distributed by location) and methodically run the primary, secondary and tertiary distribution cables and install all the appropriate busses that will be needed, labelling each wire at each end before needing to connect anything at the terminus. No confusion with lots of wire, no concerns of will there by a problem with overloads.

I used to use the tape numbering rolls, but it was a pain, and they kept unraveling and making a mess over time. Now I use a Brother label maker, type in the name of the wire and its code and wrap it as a "flag", which is easier to read when packed with many other wires in a small, dark place. The photo is an example of a temporary label I am using for my refrigerator box interior lighting wiring, for which I haven't created a code yet, nor connected the selector switch to the circuit. My reefer has a choice of red night lighting, low and high intensity LED lighting, all controlled with a magnetic switch in the doors of the reefer. Without coding or labels, madness like this would be truly a challenge.

Someday, I will get around to making a schematic, but it will be much easier using the spreadsheet as the guide, and the coded flags make it easy to follow in actual practice.