Does Power Wire for Trailer Wiring Harness have to Go to Battery on a 2013 Ford Edge SE

Updated 06/17/2014 | Published 06/16/2014

Question:

The instructions say to route the DC power wire forward to the engine compartment. Why cant the auxillary DC outlet in the cargo compartment be tapped as the power source? It is rated at 12VDC 180 W which equals 15 amps current draw.

asked by: Harry P

Expert Reply:

There are several reasons why you are not supposed to use any other power source to install a powered trailer wiring harness such as # 118515.

First, attaching the wire to the vehicle battery is part of what gives the circuit protection between the vehicle and trailer wiring. If that wire is installed anywhere else you will lose that protection.

Second the converters are not tested with or rated for a connection to any other power source. Installing it in a manner different from the instructions could result in unwanted trailer wiring harness behavior and it will void the warranty.

And third, often times components on a vehicle share fuses and relays, but not always. It is possible that the draw from the trailer lights could overload a shared circuit or a short on the trailer end could damage more than just one component on the vehicle, however unlikely it may be.

Considering the complicated wiring manufacturers are putting into vehicles these days the best solution and the safest one is to go ahead and connect the wire to the battery.

It isn't all that difficult, it just takes some time. I have included a link to a help article with tips on routing the power wire for you.

expert reply by: Michael H