How to Wire a Light Bar on Boat

Unless you’ve got a really fancy boat, I bet its lighting system is average at best. Most manufacturers only add one single light source and it leaves a lot to be desired. The big question is – what can one do to fix that? Well, how about adding a LED light bar on the boat? That way, you’ll be able to keep the lights on when it gets dark.

Plus, with a new bar, you can signal friendly voyagers. Besides, some US states require cruisers to have proper lighting installed. Now, you might think that wiring requires a scientific degree and lots of expensive tools, but I’m happy to say that any boat owner can get it done. So, join me, and let us get to wiring!

Getting Started

First things first, “park” the boat on an even surface. That way, it will be much easier to mount and wire the LEDs. And if you’ve got some factory lights installed, go ahead and remove them. Most likely, a socket wrench will be the best tool for that. Depending on how big (or, rather, wide) the new lights are gonna be, you might need to add an extra metallic bar to the back of the boat so that it holds the LEDs steadily.

There’s nothing to it: just grab your favorite drill, or order one online (these are available for 40-50 dollars) and make a set of holes in the bar and the factory brackets. Next, put the smaller brackets through (they should come with the new LED light bars for boats) and secure everything using the nuts, bolts, and washers from the package.

Splicing the Wires Together

Alright, now let’s get to the meat and potatoes: wiring the LEDs and lighting up the boat. For my setup, I installed three LEDs in the front of the boat (two smaller lights on the sides, and one in the middle), and one in the back. Now, most LEDs have pretty short wires. That means we’ll need extra wiring to pull this off. And make sure it’s at least as thick as the wires coming out from the lights.

I strongly recommend connecting all the positive wires from the separate LEDs together (essentially, turning four wires into one). That way, it will be much easier to get things right. Do the same with the negatives. Oh, and don’t forget to tape the wires. I would also solder them so that no wire will get pulled out when the boat starts to rattle or you suddenly hit something.

Routing the Wires and Getting a Switch

Ok, so, moving on with our “How to wire a light bar on boat” guide, we’ve got two main cables now – a positive, and a negative one. All that’s left to do is run them into the boat’s dashboard. Put them through the tower and the gunwale. You might have to drill some holes for the wires, so, keep that drill close. And it’s always a good idea to leave some slack wire lying around since it’s pretty cheap.

There’s nothing worse than having to redo everything only because you don’t have enough wire to reach the dash. This is important: unless you know your way around wires, I would strongly recommend investing in an accessory switch. You can get one for 30-40 US dollars, and it will make wiring a walk in the park. Make sure it’s a marine-grade switch (waterproof).

Finishing Up

Put the switch in the front of the boat, and arm yourself with a 12-volt test light. Use it to probe the connections on the back of the switch until you find the one that only comes up when you turn the switch on. Connect the positive wire to it. And what about the negative, you might ask? We’re going to use it for grounding. Without proper grounding, you’ll run the risk of damaging the LED boat lights beyond repairs.

Look under the dash – you should find a thin metallic bar down there. Connect the negative wire to it to avoid any voltage spikes. By the way, the boat’s battery’s negative cable also runs into this bar. A quick note: if you got an accessory switch that was specifically designed for boats and LEDs, this is actually it. However, on some older or “universal” switches, the amperage might be all wrong.

So, check on the fuse and switch it if necessary. And if you’re on a tight budget, but still want to install LEDs on your boat, you can make do without a toggle switch. However, that’s only possible if you’ve got two light sources in the chain.