Electrical and Lighting Accessories for Boats

Marine Lighting Products and Electrical Components for Boats Resources and Information

Maintaining the lighting and electrical system of your boat and trailer is important for ensuring that you stay safe and in compliance with the law when out on the water. Fortunately, PartsVu offers a complete selection of marine lighting products and electrical components for boats and boat trailers. Shop products from leading suppliers, like Marico, Blue Sea Systems, Boat Buckle, Marpac, and many more.

Looking for more boating and marine products? Check out our complete selection of Products and Accessories or browse electrical and lighting accessories for boats by category, including: 

• Lighting
• Battery Chargers - Inverters - Converters - Isolators
• Battery Hardware & Maintenance
• Shore Power & Accessories 
• Electrical Tools 
• Electrical Hardware & Accessories

Electrical and Lighting Accessories for Boats FAQs

What makes Marico Marine Group products unique?

Marico Marine is an independent marine consultancy providing solutions for ports, harbors, and offshore energy sectors worldwide. We led the way for mariners to embrace the arrival of Risk Assessment into the shipping world. With our marriage of salt and science, we combine technology with practical marine expertise.

Today, Marico has evolved into a Group, able to offer a 24-hour global service with offices in Southampton, UK, and Wellington, NZ. Our disciplines include Harbour Masters, Master Mariners, Marine Engineers, Naval Architects, Hydrographers, GIS Specialists, Electronics Engineers, and Environmental Scientists. We offer a wealth of experience and technical innovation with a solid reputation built on integrity and competence.

Our clients include Harbour Authorities, navigational regulators, port and offshore developers, government agencies, flag states, shipping interests, P&I clubs, and the renewable sectors.

What is Blue Sea Systems’ product guarantee? 

Blue Sea Systems stands behind its products for as long as you own them. Blue Sea Systems will replace or issue a credit for any of its products found to be defective in materials or manufacture. P12 Battery Chargers and P12 Remote Displays are warranted for a period of five years from the date of first purchase. Digital Meters and Vessel System Monitors are warranted for a period of three years from the date of the first purchase. No compensation will be allowed for products not returned to Blue Sea Systems for analysis, nor will compensation be made for the labor required to replace any defective product. Please contact Customer Service for an RMA number prior to shipping any product back to Blue Sea Systems.

What’s the difference between the types of trailer wiring harness plugs and harnesses? 

Plugs and sockets are the connectors that allow you to plug your trailer into your vehicle. The shapes of the plugs and sockets vary, but flat, round, and RV blades are the most common options.

Flat

On flat connectors, the pins line up in a row.

Round 

These connectors are round, with the pins arranged in a circular configuration. On six-pin connectors and higher, there’s also a pin in the middle. Round outlets and plugs also have round pins and holes

RV Blade

RV blade connectors are round, with the pins arranged in a circular configuration. On six-pin connectors and higher, there’s also a pin in the middle. RV blade plugs and outlets have rectangular pins and holes.

What are the different kinds of wiring harnesses?

One pin is ground on every connector in a trailer frame, so a four-pin connector will facilitate three functions. A five-pin connector will allow four functions. A four-pin connector is the most basic controlling turn signals, brake lights, and taillights—the lights needed for safety and required by the law. Upgrade to a fifth wire, and you add either backup lights or electric brakes, depending on the plug.

Standard wiring color code for a four-pin connector: 

Ground = white

Tail/running lights = brown

Left turn/brake = yellow

Right turn/brake = green

A six-pin trailer wiring connector allows you to add a 12-volt connection, which is more about convenience than safety. The sixth pin is a “hot lead” that will enable you to charge a battery in your trailer. Boaters generally don’t need this sixth pin, but it comes in handy if you are towing a camper. All you need to do is plug the adapter into the tow vehicle connector and plug in the trailer tongue. Here, the full-length plug shell ensures positive latching.

The seventh pin allows you to add yet another capability. Like the six-pin wiring harness, generally not needed by boaters, but convenient if you are hauling a camper or something of that nature.

Should I use a wishbone wiring harness or a crossover wiring harness?

Most boat trailers are configured with a wishbone wiring harness or a split Y harness that splits the running light circuit at the trailer connector so that you don’t have to run a jumper wire from one taillight to the other.

The yellow/brown wire is the running light circuit for the driver’s side. The green/brown wire is the running light circuit for the passenger side. Either wire will operate the running lights for the trailer; they are split to make it easier to wire to the taillights.

Less commonly, your trailer may be wired with a crossover wiring harness as the main harness. This wiring configuration means that the wiring runs down one side of the trailer and across between the taillights.

What gauge wire should be used for trailer wiring?

When it comes to the trailer light wiring, a 16-gauge wire is generally recommended for a 4-pin harness or a 5-pin harness. However, for a 6-way or 7-way trailer connector, a minimum of 16-gauge for the turn signals, brake lights, reverse lights and running light wires. The suggested minimum for the ground wire, brake power, and battery hot lead wires is 12 gauge.

How can I reduce the instances of faulty lighting?

Faulty trailer lights can often be caused due to a weak ground; hence it is important to ensure that the ground on the tow vehicle is connected to a plain, unpainted surface on the chassis. Moreover, each light assembly should be grounded to the trailer.

What is the use of a wiring harness in towing a vehicle?

The trailer hitch on your tow vehicle allows you to tow a trailer, but you need a wiring harness to power and appropriately control the lights on the trailer – turn signals, brake lights, running lights, etc.

How do I troubleshoot my boat trailer lights? 

Plug a tow vehicle tester into your vehicle’s tow connector to make sure the proper voltage is being pulled from the vehicle. You can buy testers very inexpensively from PartsVu or another retailer. If the tester does not light up, the problem is with the vehicle, not with the trailer’s wiring or other components on the trailer.

Clean your vehicle's tow hitch plug with an electronic contact cleaner and a little bit of sandpaper. Also, clean the connector plug. Spray the connector with an electrical contact cleaner and a little bit of sandpaper or an emery board to clean the contact pins. Finally, apply a little dielectric grease.

If the lights are dim, they only work sometimes, brake lights flash when the turn signal is turned on, or other strange things are happening, and you may have a ground wire problem. Actually, grounding problems are the cause of many boat trailer light wiring system problems, and it is a simple issue to fix.

Find the ground screw on the boat trailer — it is almost always a white wire. Disconnect it, clean the ground strap with fine sandpaper, spray with an electronic contact cleaner, and apply some dielectric grease to create a good contact. If the ground screw itself is corroded, replace it with a new one.

If you have incandescent trailer lights, it could be a bad trailer light bulb. Remove the bulb and clean the contacts with fine sandpaper, spray a little electronic contact cleaner, put a little dielectric grease on the base of a new bulb, and screw it in.

To clean corroded sockets, remove corrosion with fine sandpaper, and if you need to, use a small dowel to get into tight spaces. If the light still doesn’t work, you may have corrosion in the socket at the contact points.

Attach fine sandpaper to the end of the thin dowel – a hot glue gun works well for this. Clean the contact points by spinning the dowel and moving it side to side.

Spray with electronic contact cleaner, and finally, put a dab of dielectric grease on the contacts and insert the bulb. If the light still doesn’t work, check the mounting bolts for the light to make sure they’re making clean contact with the trailer frame.

If you see corrosion, remove it with your sandpaper and recheck the lights.