Wiring tips from Don Berry, Ph.D. Rule #1 -­‐ I spend time in salt water. I have a saying about boat wiring, “You can do it right, or you can do it again . . . and again . . . and” Not only that, but the best place to have wiring troubles on your rig is when it is in the garage. Maybe you are born lucky, but this seldom happens to me. If wiring messes up on you at the wrong time, much worse can happen. Think sunk boat. MATERIALS (and how to use some of them) Wire – If you are doing some new wiring, use “marine” or “salt water” wire. It is tinned copper and withstands harsh environments much better. (When you strip a piece of old “regular” wire and the copper is all black, then you will understand.) Unless money is no object, try to find a source other than West Marine. Boater’s World may be a bit better, but not much. You can probably get by with two (three at most) sizes other than the “big cable” you need for battery, trolling motor, winch, etc. If you are rigging a boat and stick to only two sizes (excepting the “big cable”) find a good source and buy 100’ spools. This will save you frustration and probably money in the long run. I suggest #10 and #14, red and black duplex, but that’s just me. (I won’t make my supply source public until I get permission from the person who gave me the source.) Dow Corning® 4 Electrical Insulating Compound – Find a local source and get a tube or two. (http://www.dowcorning.com/applications/Di
stributorFinder/Default.aspx?prod_id=019031
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E) (or Google “Dow #4”). This stuff keeps the environment away from joints and connections. It does not cure like “RTV”, but is like thick grease that gets all into the wire and around the connection. It is silicone based, so it lasts, but it never hardens. See “Syringes and needles” below under “TOOLS.” The syringe saves you a lot of Dow 4 and puts it where you want it. This stuff goes on every solder joint, under every piece of heat shrink (unless it is the expensive heat shrink that already has “glue” inside it), and inside every connector. Slide the needle in along the side of each wire that goes into the “back” of factory connectors (such as the ones on the B&S engines) to inject Dow 4 into the backs of the connectors. Most of the wires in factory wire harnesses are not marine wire, so the Dow 4 really helps here. Try to put some in the “front” of the connectors, where the terminals slide together, as well. Put some in you nose, ears, and under your fingernails (j/k on that last part.) Anderson connectors – Anderson connectors, sometime called “fork lift connectors”, are wonderful (Google them, and shop around for price!) They are the best ever to quick connect a trolling motor, MUCH better than conventional trolling motor connectors. I use them many other places as well, anywhere I need a high amperage quick disconnect, like the big front spotlights when they had high wattage incandescent bulbs. These connectors are made of polycarbonate, stainless steel, and silver plated copper, all good materials for a marine environment. This is hard to explain, but there are no male and female halves, yet they are impossible to hook up backwards. When you have one in front of you this will make sense. They “self clean”, meaning they wipe the contacts as the connections are made and broken, and they connect with a satisfying “snap.” They come in colors, and the colors will not connect to each other. This prevents you from connecting a 12v device to a 24v source and vice/versa. The 50 amp size is about the size of a Zippo lighter, and can use up to #6 wire. I have never used anything other than this size. You connect the wire to the “contacts” and then snap the contacts into the body of the connector. Be sure to buy the right contacts for the wire size (#6 or #10 for the 50 amp connectors.) A good supply source will sell you extra contacts, and I suggest you get a few for when you mess one up. In other words, messing up a contact doesn’t ruin the whole connector. Connectors and terminals – Use terminal ends! Twisting bare wire around a screw won’t do! (see Rule #1.) If you are forced to do this at least form a loop or hook and make it solid with solder. For ring terminals, I use bare connectors or take the insulating sleeve off. A bare connector soldered, treated with Dow 4, and the connection covered in heat shrink is as good if not better connection, is trim, and is MUCH cheaper than the expensive crimp and heat shrink ring terminal. I do use those expensive terminals and connectors, but only where I have to. I seldom “hard wire” anything in (see “Plan to replace devices” under “PHILOSOPHY” below.) For connections I may need to break, but not often, if the wire is small enough I often use what are called “bullet” connectors, but I strip off the plastic covers. Solder the wires to the connectors, put the connector together, then use Dow 4 and heat shrink tubing on the connection. This is a connection you can trust but it is reasonably easy to replace the device assuming you can get to the connection in situ to heat new shrink tubing. Getting the plastic off the female bullet connectors can be tricky. I file the insulation from the side until the metal part you crimp is exposed, then the part you want comes out easily. This seems a pain, but doesn’t take long once you are practiced, and it is MUCH cheaper than the expensive crimp and heat shrink connectors. (I have never been able to find “bare” bullet connectors.) Now, I sometimes do use the expensive crimp and heat shrink spade type disconnects. I use the ones that have a cover over both the male and female part. Thus, the covers overlap as the connection is made. I use these when I think I may have to undo the connection more often than when I use the bullet connectors. You cannot use bullet connectors on wire larger than #14, so for big wire I use these connectors. You can sometimes use these connectors where the wire changes sizes. For example, I run BIG bilge pumps, a 1500 and a 2000. The wire to these is #10, because there is no reason to run a big pump then starve it for power. But the wire on the pump is much smaller than #10. So, a #12-­‐10 yellow colored connector will mate up fine with #16-­‐14 blue colored connector. (Check this for the ones you use before taking this tip as “always true.”) Another place I use these connectors is to connect to switches that have spade terminals. Alphametals brand Liquid Rosin Soldering Flux -­‐ I find this at my well equipped local hardware store. Maybe there are other brands. Even using rosin cored solder (NEVER use acid core on electrical!) I find extra flux comes in handy and makes for good easy flow solder joints. PHILOSOPHY Craftsmanship -­‐ Every joint I make gets three things: 1) It is soldered, 2) coated in Dow 4, and 3) covered in heat shrink tubing. Terminal ends such as “rings” or “eyes” get the same treatment where the wire connects. You might get by with Dow 4 and crimping the “regular” insulated connectors, but see Rule #1. The only exception is the expensive crimp on terminals or connectors with heat shrink tubing. You cannot solder these. Ground path -­‐ DO NOT use your hull for ground! This can cause all sorts of issues, the worst being that you create a galvanic corrosion situation. Remember that the ground wire must carry as much current as the hot wire, so it needs to be just as big. Plan to replace devices – I like to avoid “hard wiring” in lights, bilge pumps, or any other device because I believe good wiring will outlast most devices. So, I put in connectors from the beginning assuming it will save me time and trouble in the long run when I need to repair or replace the device. (See “Connectors and terminals” above.) Use enough fuses – This is really a luxury, but I like a fuse per device, meaning one fuse for the running lights, one for the GPS, one for the depth finder, one for EACH bilge pump (you should have TWO), etc. This makes finding any problems easier. It also means a device that blows a fuse won’t disable other devices. NEVER put both bilge pumps together on the same fuse! That is plain stupid. TOOLS Nail clippers – The ends of wire ties cut with diagonals are sharp. Use common nail clippers, big ones, to cut the ends off flush and as slick as expensive tools. Syringes and needles – Farm supply stores (Tractor Supply is a good one for me) will sell you syringes and needles. For most things, like Dow 4, you need a short big bore needle (1” 16g.) They are SHARP!, so file off the point but leave some of the angle cut that made the point. This helps you slide the needle in where you need to. If you don’t need to “inject” the material, you can use a syringe with no needle to make a nice easy to use dispenser. (I keep Dow 4 in both kinds, without a needle to just smear it on a connection, and with a needle to inject into connectors.) Crimpers – When you do crimp, don’t use pliers! The crimper/stripper/screw cutter, “all in one” electrical tools are cheap. Get a couple of different styles. Some where the crimpers are on the ends of the jaws, as opposed to back behind the hinge, are nice. Soldering gun – Get a good pistol style (Weller is good.) For big wire, like lugs on #6 and larger, you need a big high wattage gun, so you really need two. (I once had a big Sears Craftsman gun. One time when I was really pushing it, soldering a big connection, the entire end that held the tip fell off. Why? Because the damn end was SOLDERED to the coil! I’m a big fan of Craftsman tools, but that one wasn’t the reason!) I hope this helps some of you. I didn’t get into running wires and keeping things neat. But neat, clean wiring not only looks good, it is much easier to diagnose. Following are some pictures of my small “console” that is on the bench seat in front of where I sit to drive, and what it looks like when the console is hinged up.