Trailers are required to have running lights, turn signals and brake lights. The best way to connect these lights together is with a T-One Connector. The T-One Connector is pre-wired to a 4-pole flat that can adapt to a 6 or 7 way round connector. You still must locate the proper wires which can be found in the owner’s manual or found on the chart at the bottom of the page.
There are various types of connectors. The connectors may have four to seven pins that allow for the transfer of power for the lighting as well as auxiliary functions. Functions such as electric trailer brake control, backup lights, etc. Choose a connector based on the number of pins for the function needed. The connector should be mounted on the vehicle. When mounted on the vehicle, it will display a clean look and avoid potential problems associated with leaving a connector dangling.
4-Way connectors are available allowing the basic hookup of the three lighting functions (running, turn, and brake) plus one pin is provided for a ground wire.
6-Way connectors allow the basic hookup for running, turn, and brake. There are two extra pins in addition to the ground pin that provide two additional functions.
The Diagram below shows the proper way to wire the connector to your trailer or vehicle.
Note: The black (12V) and Blue (Electric Brakes) may be reversed to suit trailer. Horse Trailers may use the center pin for 12V hot lead, R.V. trailers use the center pin for electric brakes.
Besides the three main lighting functions, additional pins are available for auxiliary power, trailer battery charging etc.
5-Way connectors allow a basic hookup for running, turn, and the brake. The ground pin is available to provide support for another function. Usually the 5-Way Flat connector is used for trailers with surge brakes. The additional wire is connected to the backup lights and disengage the trailer’s brakes when the vehicle is reversing.