Trailer Wiring Junction Box Diagram - 7-Way Wire Color Codes & Brake Signal

This document is an annotated photograph of a trailer wiring junction box, hand-labeled to show how wires connect between a tow vehicle and trailer. The left-side legend identifies the trailer-side wire color functions: blue for brake signal, green for right turn and stop, brown for tail and running lights, yellow for left turn and stop, two terminals marked 'not used,' and white for ground. The right side of the image labels the vehicle-side wiring entering the junction box from bottom to top: ground, 12V power, reverse lights, left turn and stop, tail and running lights, right turn and stop, and brake output. Additional callouts at the top right indicate the trailer brakes connection, showing the blue wire as the brake signal and the white wire as ground. Colored lines are drawn over the photo tracing each wire (white, yellow, brown, green, red, blue, gray/black) from the harness entry point to its respective terminal stud on the junction box. A reader can use this diagram to correctly land each wire on the junction box terminals when wiring a 7-way trailer connector with electric trailer brakes, including which two positions are unused in this installation.