Over the years I have seen just about everything when it comes to the way someone wires up a boat. From huge spaghetti messes to residential wire nuts holding wires together. Let’s just say there are a few boats that I am surprised haven’t had an electrical fire yet.
The key with any gear on your boat is to protect it. It is an investment and you want to make sure that you can keep it up and running and in top shape. Whether that is your main motor all the way down to making sure your hooks are sharp. I suppose the point I am trying to get across is that if you are going to do something, then do it right.
Recently I converted from manual downriggers to Big Jon Electric riggers. This was a very easy decision as cranking up a 10lb ball from the depths can get old. With the new Big Jon electric downriggers I just press a button and up it comes.
With this recent addition it involved a little bit of work on my part to make sure that not only the downriggers were mounted properly, but that they were powered properly as well. As with any marine implement these are to run off DC power. These units are 12vdc units and in my case will run off of my main cranking battery.
The first question I often get is “Do I need a second battery?” In my opinion No. Even though my main cranking battery is running two sonar/gps units, vhf radio, Fishhawk probe, and the new downriggers I know that I have plenty of power.
My kicker motor has an alternator that is constantly charging the battery as we troll thus keeping my battery in top shape for when we need to start the main motor. I can see my voltage right on my Humminbird graph and it is possible to watch the voltage as I am trolling. You can do the same as well by using the built in voltage meter on the dash of most boats.
Now that we have established that we have enough power let’s get to the meat of the project. Properly wiring and protecting your new downriggers. As with most electrical devices for the boat you want to make sure that you properly protect the unit from any overload conditions as well as possible issues with the wires being damaged.
The Big Jon downriggers that I have come with a 10amp circuit breaker built right in. Now for most people this can often give you a false sense of security. The circuit breaker is a must have for these units, but it is not something that should be relied on to protect your investment.
If you pull up the data sheets on most of these circuit breakers you will see that they are actually rated to hold at amperage well above their ratings for several seconds. They are designed to protect the motor and other internal parts, but they are slow to react and just relying on a circuit breaker to protect the downriggers can lead to a world of trouble.
Think about what might happen if you accidently cut the wire from the battery to the downrigger. Sparks could fly, you could ignite something in the boat and even cause a fire that will not only ruin your day, but could destroy your entire boat.
With any device that you install into your electrical system they should always be protected by a fuse. Either by utilizing a fuse panel or by installing an inline fuse at the point closest to the power source. In my case the downriggers are running straight from the battery so I chose to go with an inline fuse.
There are several different styles of fuses out there to choose from, but what I have always found best is to stick with a common style of fuse that is already being used in the boat. In my case I use ATC style blade fuses. They are cheap and easy to find at just about any hardware store or even often gas stations.
When going to install these inline fuse holders you want to keep a few things in mind. Make sure you can access it easily, buy ones that have a waterproof housing, and make sure they are sized properly for the required amperage that you are planning on protecting.
I am not a huge fan of crimped connections on a boat, but they do have their place in some applications. They do get used when putting on a fork or ring style terminal as these areas are the easiest to access and there is often little issues with items coming loose. However, when joining two wires together I highly recommend using a solder and shrink wrap technique.
Utilizing some good flux to allow the solder to flow properly into all strands of the wire, heat the wire with a good high wattage soldering gun and apply a good solder to the joint. Make sure that the joint is completely covered with solder and let cool. Slip the heat shrink over the joint and shrink down over the joint.
This technique is used to not only connect the in-line fuse to the downrigger wires, but to also lengthen the wires in cases that you need the extra length to get to the battery. You can see in the photo below I had to add on some extra wire to the cable and using solder and shrink tubing creates a clean joint that you will not have to worry about coming loose or shorting out.
Now that you have your wires run and your fuse holders properly attached to your positive lead of your cable you are ready to terminate them at the battery and put a fuse in to test it out. This is where people will often make an error. Sizing a fuse is important as you want to make sure you size it large enough to keep it from blowing every time you run the downrigger, but small enough to properly protect the downrigger.
In my case I have a 10amp circuit breaker on the motor, but knowing that the circuit breaker can handle large inrushes of current I need to go much larger with my fuse. I contacted the Big Jon factory to get the recommended fuse size, but you can often do a little research on the internet and you will find what you’re looking for.
Through years of experience the Big Jon service group had a recommended fuse size for my motor in particular. They recommended a 20amp size fuse and after a trip to the local hardware store I was ready to go.
After some off the water testing and measurements I am ready to put these new additions to work. If I had just thrown these on and not tested them out I could be in trouble out on the water if I wouldn’t have properly sized the fuse.
The key with any project like this is to take your time, think about what you are doing, and if in doubt do your research. It is your responsibility to properly take care of your equipment and to protect it from getting damaged or in some cases, completely ruined.