Why Is Separate 12V Battery Power Connection Required for Wiring Harness 118578

Updated 07/23/2018 | Published 07/20/2018

Question:

I just purchased a trailer hitch wiring kit from your company to use on my 2016 RAV4. My research shows that a typical small trailer pulls about 2-4 amps and a power outlet cigarette lighter in most cars can handle up to 10 amps. Therefore is it possible to power the wiring adapter harness through a power outlet instead of running the wires to the actual battery?

asked by: Bob C

Expert Reply:

Thank you for your purchase of Tekonsha 4-pole wiring harness # 118578 for your 2016 Toyota RAV4. You ask a reasonable question about the installation of this item.

It is not recommended to use a vehicle's auxiliary 12V power outlet to power a trailer wiring harness like Tekonsha # 118578. The reason is that doing so takes away the main advantage of using a powered converter, which is to isolate and protect the vehicle's wiring from any potential damage from a short or other fault on the trailer.

By using a separate and dedicated +12Vpower connection at the vehicle battery all of the car's internal wiring is safeguarded from damage that would be costly to repair. The linked article on routing that power wire should help you with your installation.

Also note installing the kit other than in the manner outlined in the instructions will void its manufacturer warranty.

expert reply by: Adam R