Redoing electrical connections

[RDW]

I have a 1997 boat. Looking under the navigation table at all the wiring connections, there is a lot of wires that look corroded as they are connected to devices and terminal blocks. I am thinking I should redo some or all.
Has anyone done this?
Is there a good way to prevent or slow this type of corrosion?
Give me some good advice.
rdw

[american]

I've dealt with a fair amount of wire corrosion on my boat as well. Terminal blocks increase the potential for corrosion as they leave wire exposed to the environment. Leave any copper (wiring) exposed on a boat, pass a current through it, you're going to get corrosion.

In replacing wire, try to find marine grade that's been tinned. Make connections that are sealed against exposure where possible (heat shrink wrap is great for this).

Lots of excellent details on the subject of corrosion and boat wiring to be found in Nigel Calder's book "Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems." Highly recommend you check it out:

Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems: Nigel Calder: 9780071432382: Amazon.com: Books

[mitiempo]

Originally Posted by american

I've dealt with a fair amount of wire corrosion on my boat as well. Terminal blocks increase the potential for corrosion as they leave wire exposed to the environment. Leave any copper (wiring) exposed on a boat, pass a current through it, you're going to get corrosion.

If the terminals are improperly done, I agree. Properly done the only potential for corrosion is the tinned eye screwed to the terminal black. Either a double crimp connector with added heat shrink or ideally a single crimp heat shrink connector will seal the wire from moisture very well.

This link will explain in detail with pics how this is done and tools to use.
Marine Wire Termination Photo Gallery by Compass Marine How To at pbase.com

Edit: Just noticed you have a Morris. They do it properly, but any previous owner may not have.

[Ex-Calif]

Originally Posted by RDW

Is there a good way to prevent or slow this type of corrosion?
Give me some good advice.
rdw

You need to "seal" the ring connectors and any butt connectors in the system. As mitempo says then your only vulnerability is the terminal blocks.

If you are getting black or "rust" colored corrosion on terminal blocks or ring connectors then the are likely not marine grade hardware.

If you are getting green corrosion it is likely really old copper or non-tinned copper wire. Tinned copper wire is worth it.

So the link mitemp provides shows the right tools - I have a single jaw ratcheting crimper. I like it because I can be precise in where I place the crimp vs. a double crimper and the ratcheting feature ensures a consistent crimp pressure.

I bought an "automatic" wire stripper. Basically you set a depth block and then every single wirestrip will be the same length and you wont nick any wires.

Finally my preference is not to use anything but ancor heat shrinkable connectors. I also bought a small butane torch for shrinking the connectors and heat shrink overwrap.

So strip the wire, use a piece of heat shrink overwrap cut to about the first knuckle from the end of your forefinger. Slide that over the wire, insert the wire into a heat shrinkable ring connector. Crimp it once. Using the torch shrink the connector slowly at first - you will get the hang of it when the right amount of heat has been applied. The shrinkable part gets real clear. now slide the overwrap of heat shrink tube up until it is abutting the ring connector. Heat it slowly with a torch until it is sealed.


This bit will seal the ring end of the connector pretty well.

Some people use clear shrink tube and put a label under it to identify the wire. This is a great idea but I find it slow. I have a cheapie brother label maker and I just label it like a flag wrapped around the wire.

I can make a joint in less than 2 minutes.

Originally Posted by mitiempo

If the terminals are improperly done, I agree. Properly done the only potential for corrosion is the tinned eye screwed to the terminal black. Either a double crimp connector with added heat shrink or ideally a single crimp heat shrink connector will seal the wire from moisture very well.

This link will explain in detail with pics how this is done and tools to use.
Marine Wire Termination Photo Gallery by Compass Marine How To at pbase.com

Edit: Just noticed you have a Morris. They do it properly, but any previous owner may not have.

Here are some pics of the spaghetti mess that was in my boat.

Photo 1 - Spaghetti
Photo 2 - House wire used on a boat? Black corrosion
Photo 3 - Non-marine grade terminal block - red rust
Photo 4 - A collection of garbage wire and Walmart connectors
Photo 5 - Amateur hour butt splice
Photo 6 - Alien wire?

[Stu Jackson]

Originally Posted by RDW

........ I am thinking I should redo some or all.

...........Has anyone done this?

rdw,

I'm sure you've grokked that everyone on this forum has an electrical system that has never needed to be maintained.

We ALL have this task, it comes with the boats.

It's called Basic Maintenance 101.

The TRICK is to get the right tools and the right materials, and then learn how to use them

The links provided by the respondents are very good.

Charlie Wing also wrote a pretty good book about it, in addition to Calder's. Wing's is more basic, depends on how you like to learn.

[Ex-Calif]

Here are some snaps of my rewiring in it's beginning stages.

The wires aren't fully dressed out yet but you get an idea of the ring connector assembly.

Photo 1 - Power switch and battery installation
Photo 2 - Electrical panel temp set-up showing DC positive distribution bus, DC un-switched fuse box and dc negative bus
Photo 3 - Electrical panel front
Photo 4 - Battery fuse and Solar controller detail

Lot's getting done today and tomorrow. Will share more of the panel setup if I can.

[exMaggieDrum]

If I had the extra money I use heat shrink terminals on all my wiring. But I don't and sometimes using a heat gun or other heat source is just not workable in tight quarters.

I have put on thousands of good quality tinned terminals that are not heat shrinked and they will last probably as long as you have the boat if you put them on tinned wire and keep them dry. Wet terminals will corrode very fast. Put in drip loops to at least prevent water from dripping into the terminals. Drip loops also give you extra wire in case you do have to replace terminals - something that has to be done at times.

Butt connectors seem to go bad quicker or are harder to get good crimps on for some reason though and I will sometimes use heat shrink ones or put light duty heat shrink on them. (Talking wire from 8-18 gauge - not bigger. I always put heat shrink on bigger terminals).

Buss bars and terminal strips are the best way to connect many types of wiring - especially if you are redoing wiring. Use high quality, preferably tinned, buss and terminal strips. Don't go cheap here.

Use either ring terminals (which I hate since you end up losing about 10-20% of the screws) or locking forks for buss bars or to any screw type connector.

Get a good crimper and use it right. I will get the wrath of purists here but I routinely use the plier type of crimpers with good quality terminals. I can't full them off if I do them right and they will fit in to tight places where the ratcheting types will not, or where you can't see how well they are on the terminal and the wire all at the same time. I have had as many bad crimps with the ratcheting crimpers as I have had with the plier type.

If you have corroded wire and you just can't (for whatever reason) replace the entire wire, then you have to cut back the insulation to where there is zero evidence of corrosion - green or even darkened copper - and that is where you have to put your terminal. If that is too short you should replace the whole wire, or if that is absolutely not possible, put a really good butt splice and try to use the same color wire at least.

And - if you are going to all the trouble - trace the wires so you know what they are for and label them. Even sketch out the terminal strip and show the color and use for each wire if you can't label them all. Put this in the bank vault with all your other most valuable papers. You will not regret the time you took to do this. I guarantee you will have to go back and figure it all out again and you will thank all that is holy that you did that the first time.