A Comprehensive Guide on How to Properly Hook Up Trailer Lights

The task of hooking up trailer lights may at first appear daunting, but with the right knowledge and tools anyone can do it. Doing so will add safety and comfort while travelling with your trailer on highways and country roads. Whatever type of lighting system you have, this guide will provide the detailed steps needed to make sure everything is hooked up correctly.

Know the Types of Lighting Systems

Before beginning, you should be aware of the various types of lighting systems used on trailers. 4-pin flat connector systems are the most popular and are commonly used on boats, utility, and recreational trailers. 7-pin round connector systems are typically found on larger trailers like semi trailers or horse trailers. It's important to become familiar with these different types of lights and connectors, especially if you plan on towing multiple types of trailers.

Understand the Wiring Schematic

In order to properly hook up the trailer lights, you will need to understand the wiring schematic for whatever type of lighting system you're working with. Thankfully, wiring diagrams can easily be found online and should be printed out prior to beginning. These diagrams will tell you which connections go to which lights and will serve as a helpful guide while connecting the wires.

Gather Necessary Tools and Supplies

There are several tools and supplies that you will need to properly set up the trailer lights. Most important are the connectors, either 4-pin or 7-pin depending on the type of lighting system you're dealing with. You'll also need wire, wire cutter/stripper, a test light, and electrical tape to ensure all connections are secure.

Connect the Lights to the Trailer

Once all the necessary supplies have been gathered, the next step is to connect the trailer lights. Start by stripping back the insulation from the wires, then making the appropriate connections according to the wiring diagram. Make sure to use the appropriate connectors or plugs for the specific type of lighting system. After each connection is made, use the test light to ensure that the lights are functioning correctly before moving on to the next one.

Connect the Trailer to the Tow Vehicle

After the trailer lights have been connected, the last step is to connect the trailer to the tow vehicle. Again, this will depend on the type of lighting system being used. For a 4-pin flat connector system, the wires should be connected in order from left to right (black, white, green, yellow). For a 7-pin round connector system, the wires should be connected in order from left to right (black, blue, white, red, brown, green, yellow).

Test It Out

Once everything is properly connected, it's time to test the lights to make sure they're working. Do this by turning on the headlights on the tow vehicle, then activating the turn signals, brakes, and running lights. If everything is working correctly, you should see the corresponding lights activate on the trailer. If not, you'll need to recheck the connections and ensure that all wires have been correctly connected.

Wrapping it Up

Connecting trailer lights may initially seem complicated, but with the right knowledge, tools, and supplies it's a task that anyone can master. Make sure to understand the type of lighting system you're working with, print out a wiring diagram, gather the necessary tools, and follow the proper steps outlined above. By doing so, you'll ensure that your trailer lights are hooked up safely and securely.

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