Why Can't Curt Trailer Wiring Harness be Powered w/12 Volt Power Outlet at Back of 2011 Mazda CX-9

Updated 06/01/2017 | Published 05/30/2017

Question:

The Mazda CX9 has a power outlet on the rear passenger side. Why cant we just tap into that wire and not bother routing all the way to the battery? If we do that, would we still have to install the red fuse portion of the wiring? Or does the power outlet already have that back in the fuse box. This would seem to be the simplest way to install this.

asked by: Bill

Expert Reply:

Using the 12 volt power outlet certainly would make the installation of trailer wiring harness # 56016 easier on your 2011 Mazda CX-9. But there are several reasons why it should not be installed using that outlet.

The reasons are that doing so will void the wiring harness warranty because it is not tested or designed for that type of installation. The circuit for a power outlet could be overloaded by the draw of a trailer wiring harness. And if attached to a power outlet you lose that level of circuit protection between the trailer and vehicle so if there is a severe short on the trailer it can end up damaging electrical components on the vehicle.

While running the power wire to the vehicle battery isn't the easiest way to get power to the converter box considering the problems that could occur it is definitely the safest! I have included a link to a help article with tips on routing the power wire for you.

expert reply by: Michael H