How to Install T-One Vehicle Wiring Harness # 118520 on a 2010 Mazda CX-9

Updated 05/05/2010 | Published 05/02/2010

Question:

Does install differ with a 2010 Cx9 with the tlr prep pkg? Some of the forums say that the OEM connector does not require power

asked by: Dave H

Expert Reply:

The installation of wiring harness # 118520 would go the same on your 2010 Mazda CX-9 as it would on the 2007 through 2009 models. You will definitely need to run the power lead wire to the positive battery terminal on the vehicle, to prevent your trailer from pulling power directly from the tail light circuits. This will protect your vehicle wiring system from overload.

The installation is fairly straight forward once you have gained access to the tail light connectors on either side of the vehicle.

1. Gain access to your vehicle tail light wiring harness by opening your rear cargo door and removing the threshold, and the floor panels and trays. Once these are removed, you will also want to remove the cargo loops and Phillips head screws on either side.
2. Locate the vehicle tail light harness and pull apart the connectors. The connectors with yellow wiring would be connected between these two plugs. Make sure the connectors are clean, and that you hear a solid click as they lock together.
3. Route the connectors with the green wire below your threshold cover to the tail light housing on the passenger side. You would repeat the connection on the passenger side, just like you installed the connectors on the driver side.
4. Back on the driver side, locate a flat surface in a out of the way spot and mount the black converter box with the double sided tape.
5. Locate a suitable grounding point near the connector, such as the vehicle frame or a cross member. I would recommend giving the area a light sand, just to remove any lingering buildup. Drill a 3/32 of an inch hole and secure the white ground wire using the included screw.

Once these connections in the rear are made, you would then run the 12v power lead to the front of the vehicle using the included black wire bundle, and connect it to the positive battery terminal on your vehicle. The yellow fuse holder would be installed on this wire, before it ends at the battery terminal.

I have included a link to the instructions, which have some up close pictures which should be helpful for you.