Install Trailer Lights for Safety

Trailer Lights
Most trailers are required to have functional lights on them. These requirements are set by state regulations of the Department of Motor Vehicles. Check with your own local regulations for specific requirements. Taillights in most cases must identify turn signals, brake lights and operational running lights. Typically these trailer lights are electrically tied to the towing vehicles light system. The plugs utilized in the wiring are mated for interconnection and may have specific diagrams for the particular plugs. Use the resource link below for various wiring options.

Items:
4 - wire trailer wiring
Wire pliers
Scotch lock wire connectors
Wire strippers
Female trailer plug
Small slotted screwdriver
Male trailer plug
Metal screw (optional)

One
Identify the vehicles wiring for the following colors and usage. Typically the wire colors will follow the operation of a green wire for the right hand turn signal and brake light. The yellow wire will use the left hand turn signal and brake light. Brown wires are used for the running lights and the white wire is the trailer and vehicles ground wire tied to the vehicle frame and negative (-) side of the battery.

Two
Cut a four-foot piece of the four-wire trailer wire with the wire pliers and connect the same color wires with the press on scotch locks. You may have to separate the wires and fit the scotch lock around the individual vehicle wire. Insert the end of the cut piece of the trailer wire into the end of the scotch lock and use the wire pliers to press down the metal tab. Fold the insulating plastic tab over the scotch lock. Perform this on all three green, yellow and brown wires for the connection. The white ground wire can be electrically connected to the car frame by the use of stripping the end of the white wire with the strippers. Wrap the bare end of the copper wire under a loosened vehicle frames bolt and retighten the bolt.

Three
Strip back one inch of the trailer wire insulation to reveal the bare copper underneath. Insert the wires into the female connector. The female connector is to be used on the vehicle side of the plug. The green wire will go into the wire terminal marked "RT". The yellow wire will be connected into the terminal identified as "LT" and the brown wire into "TM" terminal. The white ground wire is inserted into the "GO" terminal. Tighten all wires with a small slotted screwdriver.

Four
Run the four-wire trailer wiring through the trailer frame and connect the wires to the appropriate lights on the trailer. Use step one for color identification and the connection to the individual lighting. Connect the rear taillights in accordance to the manufactures directions for the turn signal and running light connections. The rear taillights should be of a dual element design along with the wires coming from the fixture. One wire is for the running lights and the other is the turn signal/ brake light operation. Terminate all connections to the taillights using the scotch locks.

Five
Use the male connector on the trailer side of the wiring connection. Connect the four-wire trailer wiring in the same manner as outlined in step three. Run an extra white wire from the male connector and permanently connect this to the metal frame of the trailer. You may have to install a screw to connect the wire to the metal frame of the trailer.

Words to the Wise:
Follow all local DMV regulations. Trailers over a certain width and length maybe required to have extra running lights installed on the rear and sides of the trailer frame.