The following file (PDF file type) contains detail explanation and description on how to install the 2007 Toyota FJ Cruiser Trailer Wire Harness and its wiring diagram. During the installation process please take care not to scratch any part of the vehicle. Bind the tips of tools (clip remover, slot screw driver, etc.) with vinyl tape to prevent damage to any part of the car, or use a nylon removal tool (resin based prying tool).
The trailer wire harness system composed of following items: a converter, wire harness, plastic, plastic tie (black and brown), packing, bolt, fuse (15A), and towing trail relay.