Adding a Trailer Wiring Harness to a 2012 Toyota Highlander without Factory Tow Package

Published 09/01/2016

Question:

I bought a used 2012 Toyota Highlander from the dealership. It did not have a trailer hitch. I had a trailer hitch installed nearby. They told me that the plug in the rear did not have power and that there was something wrong/defective with the wiring in the vehicle. I questioned them about the control box that was needed under the dashboard on the drivers side and they were clueless about it. They did install the four pole connector cable and suggested I talk to the service manager at Toyota. I took the vehicle to the Toyota dealership from whom I purchased the vehicle and they told me that the same story and that it would cost $450+ to rewire the vehicle. I have viewed you installation video and have noted the installation of the control box to the white connector under the dash. I have also read where this is a required piece of the installation or there will be no power at the rear plug. Question #1: Is the control box necessary for the rear plug to have power? Question #2: Assuming the answer is yes to Q#1, is that sold separately or do have to buy the complete system?

asked by: Joe C

Expert Reply:

Yes, the converter box is needed on the 2012 Toyota Highlander in order for the connector at the back to have power. But it is not available by itself. But the cost will still be about the same because the 4-Way part of the system, such as # 118449, is the least expensive to make so it only would add a couple of bucks.

There is also a 10 amp fuse that will need to be inserted which is explained in the instructions I have linked for you. I have also linked a video showing an example installation for you.

expert reply by: Michael H