Boat Electrical System Safety Tips

It is quite common for us to receive a call or text from a boater who is experiencing troubles with his or her marine electrical in a remote anchorage.  Everything from the windlass not working to a troublesome battery bank.  We can have a technician trouble-shoot over the phone but, in many cases, the boater is missing spare fuses or the tools to make the repairs.  These items are readily available in the city, so it is worth it to spend an afternoon and ensure you have spares and tools in case of an electrical failure.  Let's take a look at the most popular items:

Basic Tools. Many electrical problems start with the connectors, the wires are in a damp environment and are subject to constant vibration.   A good connection starts with a good crimp and the secret to a great crimp tool is that it does not pierce the insulation on the wire.  Our favourite is the FTZ Cycle Crimp tool that is specifically designed for heat shrink terminals and splices.  The bare wire at each end of the connector sleeve must be sealed with heat shrink.  Make sure you have a number of different sizes, both for correct wire gauge and ring size, on board along with a good heat shrink torch, such as the Ancor Mini Butane or Butane Pro.

Marine terminals feature pure electrolytic copper to offer the least electrical resistance for best current flow.  They are tinned to prevent corrosion from salt and moisture.  Ensure that they are UL listed and designed to be used on flexible stranded wire. Look for terminals with a seamless, flared barrel design that makes it easy to insert the wire and gives maximum strength when crimped.  A closed-end seals out moisture so your cables stay dry and do not corrode over time. You may be tempted to use less expensive terminals designed for your car or truck but don't.  Just don't.

 Along with your crimper, terminals and heat shrink, you should pick up a small tinned wire brush.  To ensure you have the best connection possible, keep the posts and connectors free of corrosion

Your onboard fuse kit should include a complete set of both glass and blade fuses.  Spend a rainy afternoon and go over your boat and make a list of fuses you use.  Many marine stores carry small, inexpensive kits with a great assortment.  A really great tip is to zap strap or tape an extra fuse in or near the location of the actual fuse. If you have an inverter/charger, make sure you have a Class T fuse onboard as they can be difficult to source.

Test Equipment. Spend the money and get yourself a good digital, auto-ranging, multi-meter.  They are inexpensive and available at marine stores.  One of our favourites for boaters is the Bluesea Mini Clamp Multimeter - AC/DC, part number 8110. If you are unsure on how to properly use a multi-meter, there are a number of really great videos on the individual manufacturer's website or You Tube. The big advantage with a clamp-on meter is that you can easily measure the current flow in a wire without having to disconnect the wire. The clamp measures magnetic flux and provides an amp reading. It’s great tool to measure the current flow of any appliance, for instance the starter draw or the windlass draw.

 Maintenance. The novelist, Tom Robbins, said "There's birth, there's death and in between there's maintenance".  One of the easiest ways to ensure you have a reliable electrical system is to take care of what you have.  Secure loose wires, don’t use wing nuts on battery terminals, tighten nuts on bus bars and switches, watch for any sign of chafing and clean connectors on a regular basis. If you have flooded batteries make sure you check the water levels every month as a precaution.  Never let the plates in your flooded lead acid battery be exposed to air. Where ever possible only use spark or ignition protected devices.

 Owner’s Manuals. Those annoying little books that seem to hang around on the boat, with no particular home, until you need them.  We recommend collecting them all together and storing them in an accordion file or binder.  While all of this information is available on-line, boaters do not always have access to the internet.  The back pages of these manuals typically contain a list of common error messages and resets.  As well, most of the new equipment has built-in diagnostic tools that can help you trouble-shoot.  It is also very common, with most electronics, that when they are installed only the "basics" are set up.  Just enough to get you up and running but by spending a bit of time with the manual you can learn the true capabilities of each piece of equipment and discover some cool options that weren't mentioned on the box.  When all else fails, it may be as simple as turning the power off, disconnecting the power cord and counting to 10 before starting all over again.

Schematic Drawing. Most new boats include a drawing that outlines the entire electrical system, however these become outdated very quickly as new equipment is installed.  For older boats, they can be completely out-of-date or non-existent. Putting together a simple diagram of your boat's electrical system may seem overwhelming but it isn't as hard as you think.  It just takes time, patience and the realization that it cannot be completed in a day and will be an on-going project.  If you have an existing drawing, we recommend you enlarge it and make clear notes regarding any changes.  If you don't have a drawing, start with a large sheet of paper, and begin with the batteries and the main DC system such as battery chargers, inverter, busbars, switches, also include wire size and fuses. If you decide that this is too big a task and would prefer to hire a professional, ensure that they are ABYC certified as they can quickly recognize any deficiencies.

Labelling. In order to complete the schematic drawing, you will have to figure out what each wire is for and where it goes.  Once you have established the purpose of the wire, attach a label to identify it.  Use marine specific labels or a high-quality labeler.  Oils and moisture in the engine room can cause most home office labels to dissolve.  While you are tracing each wire, look for signs of chafing or small bumps and change as required. 

Education. Most yacht clubs, cruising groups or Power Squadrons offer electrical courses either in the evening or on the weekend.  Make a point to attend regularly to stay current, pun intended.  For those of you who really want to get to the next step of understanding the what and the why of marine electrical, purchase and read Nigel Calder’s book called “Boatowner’s Mechanical and Electrical Manual”, it is the industry "go to" for marine electrical repair.

A little preparation goes a long way and the hope is that you will never need it.  On the other hand, when someone is walking down the dock asking for a "l20A blade fuse” it's a good feeling to say "I've got one".

About the author: Jeff Cote is the owner of Pacific Yacht Systems, a full service shop delivering marine electrical and navigation solutions for recreational boats. Visit their website and blog for info and articles on marine electrical systems, projects and more: