What is the AUX Power Pin for on a 7-Way Trailer Connector

Published 03/26/2015

Question:

What is the purpose of the AUX connection. I just replaced the 7-way connector on my SUV and discovered that the AUX connection is always live with 12V even with the SUV ignition switch off. Thank you.

asked by: Larry L

Helpful Expert Reply:

Some trailers may need an auxiliary power source to power additional 12 volt items on the trailer but this isn't as common as you might think. Now instead of aux power reverse lights are more common on vehicle side trailer connectors (and still not used by all that many trailers).

If your trailer does not need aux power and you don't want that circuit live at the connector you could remove that wire from the back of the 7-Way and cap it off with a wire nut, tape it up with electrical tape and stow it out of the way. But as long as nothing is drawing power on that circuit it would be fine to leave hot all the time.

expert reply by: Michael H