How To Cut Power To the 12 Volt Pin On a 7-Way While the Vehicle is Off

Question:

I have a 2017 Subaru Forester. I am looking to install a Tekonsha Prodigy P2 brake controller. I know I need the additional wiring harness part #ETBC7. This will convert my 4 pole to the 7 pin. I don’t believe I need anything else from what it looks like. If I do please let me know. I was wondering if there is a solenoid to prevent charging or power from going from the car to the trailer when the car is off. Or if I can install one? Thanks

asked by: David T

Expert Reply:

The Universal Installation Kit for Trailer Brake Controllers part # ETBC7 will come with everything that is required to install the Tekonsha Prodigy P2 Trailer Brake Controller part # 90885 on your 2017 Subaru Forester with an existing 4-way trailer connector. If you leave the trailer connected to the tow vehicle and have circuits powered from the 12 volt pin on the 7-way or have it hooked to an auxiliary battery then there is a chance that this could then kill the vehicle's battery. Therefore, in order to prevent this you will indeed want to use a solenoid, the Battery Isolation Solenoid part # PK5231201.

expert reply by: Conner L