How to Wire Trailer Lights

Know the color coding scheme of the wires and the job is easy.

If you are considering towing a trailer or camper behind your car, truck, or RV this year, you might save yourself a possible headache, lawsuite, or worse, by making sure your trailer lights are wired and working correctly.

Things You'll Need

• 12-volt test light
• Trailer light connector
• Electrical tape

Instructions

1. Locate your vehicle's taillight wiring harness, normally found in the trunk or around the rear bumper.

2. Locate a spot for your hook up, making sure the wiring harness is long enough to reach your trailer' s connector receptacle. If it is not long enough, you will have to purchase more wire or an additional connector at your local auto parts store.

3. Use the clip end of your "test light" and clean off a small area of metal on chassis to use as your ground. Then turn the headlight switch so that the parking light is on. Using the test light, probe the wires until it lights up. If it comes on and stays on, you are ready to connect the brown wire to that wire with a quick connector. Turn your headlights off before proceeding.

4. Turn the ignition on and engage the right turn signal. Using the test connector, repeat the process of probing the test light until the trailer's turn signal comes on and stays on; this is the wire that will be the right turn signal and right brake light wire; connect the yellow wire to this wire. Turn the ignition off.

5. Turn the ignition switch on again, keep it in the "run" position and activate the left turn signal. Once again, probe the wires with the test light until the light flashes. This wire will be the left turn signal and left brake light wire; connect the green wire to this wire. Turn off the ignition.

6. Attach the white wire to your ground wire. If you do not already have a ground wire to attach to the white wire, clean off an area of metal on the chassis for your ground and connect the white wire using a sheet metal screw.

Tips & Warnings

• Know the color codes for correct fitting; the wires on either type of receptacle will be color-coded:brown wire to the tail or parking lights, green wire to right turn signal, yellow wire to the left turn signal and white wire to common or chassis ground.

• If not all lights work at first, double check the quick connectors for proper connector or check the trailer light bulbs.

• You may need to tape all connections with electrical tape to keep from having problems later.

• Be sure to put the wired trailer connector back in the trunk. If you need to, secure the connector underneath the car, but beware of exhaust pipes or the event of any road obstructions.

• The male end of the connector goes on your vehicle and the female end on the trailer or camper.

• To be safe, recheck your trailer lights about every 100 miles.

References

• eTrailer.com: Wiring Diagrams