How to Convert Five Wire Trailer Lights to a Four Prong Connector


Towing a trailer is a driving challenge because the additional weight and length tend to reduce overall braking and turning abilities. One way to lessen the added risk is to have operational trailer lights, as well as separate brakes for a large trailer. A five-wire trailer harness provides power for signal, marker and brake lights as well as electric trailer brakes. If you are towing a light trailer that has no brakes, you may wish to change from a five-way to a four-way connector, which eliminates the wire for the electric brakes. However, state requirements for trailer brakes vary, so you should review the regulations regarding the maximum allowable trailer weight without brakes prior to disconnecting yours.

Things You'll Need

  • Four-way trailer harness
  • Wire stripper
  • Butt connector
  • Pliers
  • Electrical tape
  • Cut off the end plug from the five-way trailer wiring harness leaving as much wire as possible.

  • Strip 1/4-inch of insulation from the ends of the green, yellow, brown and white wires with the wire strippers. Tape the end of the fifth wire.

  • Connect the four colored wires to the corresponding four-way harness wires with butt connectors. These work by placing one stripped wire in each end and compressing with pliers. Gently tug on the connection to assure a tight fit.

  • Wrap each connection in electrical tape, then wrap all five wires together.

  • Test the trailer lights by cycling through the brake, signal and marker lights on the vehicle, making sure the trailer responds appropriately.

Tips & Warnings

  • Disconnecting the brake power on the trailer could create a dangerous situation if the tow vehicle is incapable of slowing the trailer without them. A four-prong connector is recommended only for an approved light trailer that has no brakes.

Related Searches


  • Photo Credit Cameron Spencer/Getty Images News/Getty Images
Promoted By Zergnet


You May Also Like

Related Searches

Check It Out

How To Travel For Free With Reward Points

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!