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What To Consider When Buying Trailer Lights

Trailer lighting makes your trailer legal with your state’s Motor Vehicle department. Lights are essential for safety and letting other drivers see your trailer. In poor visibility or darkness, trailer lights are your best defense against collisions (especially rear-enders), as well as severe damage to your boat. Make sure you get high-quality trailer lights. Consider them an essential piece for boating safety.
How your Trailer Lights Function

Trailer wiring comprises a plug, which is connected to the lighting circuitry of the tow vehicle, a matching connection on the trailer, and a lengthening wiring harness.

Multi-function lights combine multiple functions into one compact fixture. These include reflectors, lighting functions, and even reflectors. This makes wiring and mounting lights a lot easier.

Shining in a Dirty, Tough Environment

Trailer lights often get the stuffing beat up by:

If hot or warm lamps are suddenly submerged into cold water, you may experience thermal shock. Submerging your lights can result in short circuits as well as corrosion of sockets and connections, burned filaments, and cracks in the plastic lenses. Saltwater corrosion is especially dangerous.
You will end up covered in road grime and other corrosive substances.
Long hours of harmful highway vibration that can weaken or break incandescent bulb bulbs and loosen the lens seals.
A drop-in voltage that is caused due to high current draw by several lights. It can occur from the towing vehicles all the way up to the trailer’s taillights.
Protruding covers for light bulbs that attract hard objects like fences, high curbs and lampposts.

Trailers with a Maximum width of 80 inches

There are two main categories of legal requirements for trailer lighting: those less than 80in wide and those greater than 80in wide. Trailers less then 80″ in width need to have tail lights. Additional side marker and side reflector lights may also be required for trailers with longer lengths.

To help define the trailer’s perimeter, larger trailers must have additional lights. The rear of the trailer needs three red identification light bars. The lights should be mounted at the required spacing. Clearance lamps, which alert drivers to your trailer’s width, should be placed at least one side (generally, on the trailer bumpers).

Matching an existing set

This quick fix might be enough to save you from lights that won’t turn on. You should clean the mounting bolts using a wire brush, before you purchase replacement lights. The mounting hardware is what connects many lights to their trailer frames. If the grounding mechanism fails, the lights may not work.

We suggest that you replace all your existing trailer lights if you have frequent problems with them. A new light set with wiring harness costs as little as $25 and can easily be installed in under an hour. It can be tricky to run wires through box section trailer frames. If this is the case, you may need to pull a messenger along before pulling the wires all out. Attach the new harness end to the old trailer plug by removing the trailer plug. Take the old harness and pull it out of the trailer.

Wiring color-codes and converters

Basic color-coding is straightforward (as shown on the Wiring Harness Function & Color Chart). Paradoxically, the ground wire is white. Even though the trailer hitch acts a ground, the white wiring should be connected to the vehicle’s ground and the trailer frame. The brown wire serves as the taillights. It runs to both red and clear lights. The yellow wire is for turning left, and the green wire (think port) for turning right.

Your trailer should not be equipped with household “wire nuts”. You can keep corrosion from your wiring by using waterproof adhesive-lined butt connectors to connect your lights. Ancor Stainless Steel Wire Cutter Crimper Crimper can be used as a quality wire cutter.

Japanese, American, European and Japanese vehicles use separate circuits in order to turn and light the brake lights. A five wire-to four wire converter will be needed if your vehicle uses amber rear indicators or has a different area used for turning or braking. These are affordable and can be attached permanently to the tow vehicle wiring harness.

LEDs or incandescent bulbs

LEDs eliminate many shortcomings of conventional trailer lighting, such as the fact that they use more electricity and are subject to vibration. LED advantages include:

Higher life expectancy: LED light bulbs have a much higher lifespan than traditional incandescents. In addition, they are more durable than conventional lights that last 3,000 hours. Also, LED lights don’t break down from vibration. This basically guarantees that you’ll never need to replace another bulb and that the lights will likely last the lifetime your trailer (except for occasional navigation errors where your trailer is backed into a fence …)).
LEDs are impervious from submersion, road grime, and a permanent seal in a welded plastic lens ensures that LED lights will not corrode or become short.
No thermal shock: LED light bulbs generate very little heat. Therefore, thermal shock from immersion should not be a problem.
Minimal voltage drop: LED lighting draws 1/8th the current of similar incandescent lamps. This ensures that there is minimal voltage drop.
Low profile LED lights: They are much more likely to be damaged in collision than protruding bulbs.
LED lights flash instantly.

Waterproof lights

Submersible lights allow water into the unit after being submerged. The “Belljar Principle” protects the socket and the bulb by creating an air pocket. It allows only a very small amount of water in the bulb, but not enough to allow it to touch the bulb. Some light bulbs are protected by waterproof “capsules” which protect them against corrosion and heat shock.

Lights that are truly waterproof such as our Sealed Oval Trailer Light Kit have a sealed design to keep water out. All LED lights have a permanent seal.

Crossover Harness or Split Wiring Harness

Most trailers use a “splitY” wiring harness. This splits at each trailer’s tongue. The wire runs down each end of the frame. All of our Trailer light kits include this type of harness.

You may have a crossover wiring harness installed on your trailer. This runs one side of your trailer and crosses between the taillights.

You Need to Inspect Your Lights

Before you move your boat to the trailer, make sure you inspect all trailer lights & brake cables. Connecting the tow car to the trailer requires a helper who can operate the controls for turn signals as well as taillights and brake lights. Do a thorough inspection at least twice a season. Examine every inch and connect any loose wires to the trailer’s frame. If you find nicks in your wiring, it could lead to a short circuit. You can inspect the wiring plug near the coupler end.