Parts Needed to Add 7-Way Connector and 12V Power Circuit 4-Pole Harness on 2014 Subaru Outback

Question:

I/ve read your previous post on the above subject. Already have Curt 4 way wiring harness installed in 2014 Subaru Outback Wagon. Need a 7 way blade adapter to charge trailer battery that i will be towing. Do I have to run power wire from the Subaru battery or is it already installed by Subaru in the wiring harness behind rear seat?

asked by: Paul S

Expert Reply:

The Curt 4-pole trailer wiring harness # C56040 which is a confirmed fit for the 2014 Subaru Outback Wagon carries only lighting signals and does not have a +12V auxiliary power circuit required to maintain the charge on a trailer-mounted battery. The factory connector does not include this function.

We do offer a kit that allows upgrading of the 4-pole wiring format to the more comprehensive 7-way format, which includes three additional circuits for the +12V trailer power feed, for trailer brakes and for a reverse light circuit (for trailers that have reverse lights). That kit is # ETBC7.

The # ETBC7 also serves as the installation kit for a hard-wired trailer brake controller, such as the excellent Prodigy P2 # 90885.

There are adapters such as # 37185 (which, please note, is one of the components included in the ETBC7) but this does not in itself add the +12V power circuit.

If you will be using a trailer brake controller to power the trailer's electric brakes then go for the # ETBC7 kit. But if your trailer has no brakes and you only need the +12V circuit for the trailer battery then use part # 37185 along with enough 10-gauge wire # 10-1-1 to reach from the engine compartment to the back of the car, a 40-amp circuit breaker # PK54540 and ring terminals # DW05705-1. This 10-gauge wire will connect to the battery + terminal, run through the breaker, and extend back to the # 37185 where it will join the black pigtail lead to complete your 12V circuit.