I am trying to add backup sensors to my 2017 STX. I would like to avoid cutting into the tail lights for power so I thought I'd try getting power from the 7 pin hitch connector. As noted in the first image, there are four conductors coming from the head unit. I connected the Red (ACC) wire to pin 4 on the plug. The yellow (R) wire to the center pin. The blue (brake) wire to pin 5 and the black (GND) wire to pin 1. In testing, the display doesn't power up. Assuming that everything else is wired correctly, did I wire the 7 pin plug correctly?
Thanks in Advance!

 

Unless there is a trailer present the truck will not energize the +12VDC at the connector.

 

I'm assuming the same thing would be true on the 4 pin connector? Thanks for your response!