Rewiring trailer lights

Rewiring Trailer Lights

by Conrad & Judy Kreuter

Do you find that your trailer lights never work? Or at least it seems that way, doesn’t it? Well, as you know, the only way to get on the road is to make sure your lights are in working order.

The best way to begin this project is to purchase a trailer light and wiring kit. Look for one labeled submersible. Remember not all kits have this feature. This kit will contain two multifunction submersible taillights (right and left hand), two side marker lights, (if your trailer is over 80 inches wide), license plate bracket, a new wiring harness with trunk connector, and mounting hardware. Most importantly, a detailed instruction pamphlet will be included to help you through the project. Complete trailer light kits cost between $30-60.

Gather together your basic hand tools including wrenches, Phillips and straight screwdrivers, and side cutting pliers. You may even need a hack saw to cut off the old light mounting screws since they will most likely be rusted together.

Remove the left and right taillights and the left and right side marker lights. Cut the wiring where it comes out of the lights leaving a couple inches of length. Use the old wiring as a messenger, that is, tape a strong thin string to the end of the wire of all four lights and pull through the trailer frame towards the front of the trailer. Once you have the messenger string at the front of the trailer, tape the new wiring to the messenger string and pull back through the frame to the original light locations. Connect the new wiring to the new lights following the directions that come with the kit. Fasten the completed light assemblies to the trailer frame. If you don’t wish to run the new wiring within the trailer frame, you can use plastic wire ties to fasten the wires to the outside of the frame.

Connect the new trailer 4-wire connector to your vehicle. Test to make sure the trailer lights are working by pushing on the brakes and turning on the left and right turn signals. The side marker lights should come on when the headlights of the vehicle are turned on.