Which Pin on 7-Way Trailer Connector Carries 12V Charge

Updated 03/15/2017 | Published 03/14/2017

Question:

Which one would you use to charge a trailer mounted battery anytime the trailer is plugged in? Thanks

asked by: Richard C

Expert Reply:

On a vehicle 7-way type trailer socket the wiring configuration can be in several different formats. If you refer to the linked article you'll be able to see photos of the common function assignments for each pin. Usually the socket pin at the 1-o-clock position wil carry the 12V auxiliary power feed for the trailer battery.

Most vehicle wiring will have this power feed controlled by the ignition key to avoid accidentally discharging the vehicle battery.

expert reply by: Adam R