Does Power Wire have to be Run to Battery to Install Trailer Wiring Harness on 2015 Ford Edge Sport

Updated 03/08/2018 | Published 03/07/2018

Question:

Is there some where else to connect the power supply within the vehicle rather than running a separate power wire all the way to the battery?

asked by: Will W

Expert Reply:

Powered trailer wiring harnesses like # C56292 have a direct connection to the battery for 2 reasons. First, it powers the trailer lights instead of drawing the power and the signals all through the vehicle tail light wiring. This helps protect the vehicle wiring. And second it offers additional circuit protection beyond what a non-powered converter can.

If wired into a rear power port that port could be overdrawn or a short on the trailer side could cause that power port and anything else on that fuse to stop working. The harnesses are not tested, rated, or warrantied for any other installation method.

Basically, you want as much isolation between the vehicle sensitive wiring and electronics and the trailer wiring. The last thing you want is a trailer short damaging the vehicle. If there were a short it would blow the fuse or converter and not damage the vehicle electronics.

Many people think that making the connection to the battery is going to be a lot of work. Really it is not much more work, it just takes a little longer. I have linked an FAQ article I wrote with tips on routing the power wire.

expert reply by: Michael H