Odyssey has been produced by the Honda Motor Company since 1994. All Odysseys are delivered with a factory-fitted flat four-pin hitch installed adjacent to the tow package. A flat four-pin hitch is suitable for use only with small, light-weight trailers; for more substantial loads a round seven-pin hitch must be installed. The additional three wires convey signal from an electronic brake controller, an auxiliary often used for reversing lights and a 12-volt hot supply.
Insert your fingers below the hard plastic kick panel on the left of the driver's footwell; draw the panel upward and outward. Use the same method to remove the step panels below both the driver's door and the rear sliding door. Lift the spare wheel out of its well, and remove the cover from the jack storage area.
Run a 10-gauge blue wire from the brake controller wiring harness down the exposed left-hand-side of the driver's footwell to floor level. Route it through the exposed channel beneath the driver's door, slip it beneath the carpet at the "B"-pillar, then continue along the channel beneath the sliding door. Route the wire through the spare wheel well into the jack storage area.
Identify the trailer light control module, a black box approximately 3-inches by 1-inch by 1/2-inch deep, secured to the Odyssey's body above the jack. Follow the wires emerging from the module's right side to where they pass outside the vehicle through a grommet. Route the new brake controller wire through this hole alongside the pre-existing wires.
Find the end of the new wire outside the Odyssey by reaching up between the bumper and the splash guard. Pull the wire through the grommet until there is enough length outside to reach the trailer hitch.
Route a 10-gauge black wire from the positive terminal of the battery down through the engine bay and along a chassis frame rail to the location of the trailer hitch. Use a plastic zip tie approximately every foot to secure the wire. Fit a 30-amp inline fuse holder within 6-inches of the battery pole, but do not install the fuse.
Use wire cutters to cut the flat four-pin hitch off its four wires as close to the end as possible. Connect these and the new wires to a round seven-pin hitch as follows: white wire to terminal one, blue wire to terminal two, brown wire to terminal three, black wire to terminal four, yellow wire to terminal five and green wire to terminal six. If making an auxiliary connection, use 14-gauge purple wire and connect it to terminal seven.
Replace the interior trim panels, the spare wheel and the jack cover by reversing the removal sequence. Install the 30-amp fuse.
