How to Install Lights on an 18-Foot Trailer

Trailers in all states are required to have lights that work in conjunction with the tow vehicle lights. An 18-foot trailer would be required to have rear lights and side marker lights permanently mounted. Installing these lights on a trailer is a project for a do-it-yourself handyman that can be accomplished in a few hours using simple hand tools.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Trailer light kit 3M Scotchlok connectors

1. Using the supplied hardware, mount the trailer lights to the rear of the trailer. Be certain to mount the lights with the clear lens on the bottom on the left side of the trailer. The license plate bracket will mount with the tail lamp in states where it is needed.

2. Mount the light bar in the center of the rear of the trailer if the trailer is over 80 inches wide. This light bar is not required for narrower trailers. Install the light bar with self-tapping screws.

3. Use self-tapping screws to mount one side marker light on each side of the trailer just forward of the fender.

4. Run the multi-conductor cable down the left side of the trailer. Leave enough slack at the connector to allow the trailer to turn corners.

5. Connect the brown wire to the taillights, side marker lights and the rear light bar. Make connections to the taillights using solderless butt connectors and to the side and rear bar light using 3M Scotchlok connectors.

6. Connect the green wire to the right stop/turn lamp using a butt connector.

7. Connect the yellow wire to the left turn/stop lamp using a butt connector.

8. Cut the white wire and use a ring connector and self-tapping screw to attach it to the trailer frame.

9. Tape all connections, and secure the wiring cable to the trailer with nylon wire ties.

10. Connect the trailer to the tow vehicle. Turn on the vehicle lights and check for proper operation of the trailer lights.