Is a Battery Connection Required when Installing a Trailer Wiring Harness on a 2012 Toyota Venza

Updated 11/30/2012 | Published 11/26/2012

Question:

Do I have to run the 12V black wire from circuit protector to the + terminal on the battery to use this quick connect t-wiring harness? There should already be power to the rear lights? If so, this is not a straight forward connection.

asked by: Marc

Expert Reply:

The Curt trailer wiring harness # C56079 does require a direct connection to the vehicle battery. This is what will power the trailer lights. It is designed this way to protect the sensitive wiring on the vehicle from any shorts that could end up damaging the vehicle wiring and/or electrical components.

The connection has to be made at the battery and not any other location because the harnesses have not been tested for use from an alternate power source. While there is power that runs through the light wiring on the vehicle it is not sufficient for the extra power draw from the trailer lights. The harness will not work if it is not connected to 12 volt power from the battery.

Routing the power wire is not as difficult as you might think, though it can be time-consuming. I have included a link to an FAQ article with tips on routing the power wire.

expert reply by: Michael H