Trailer wiring B+ charge wire question

[Z1500]

On my 2020 2500HD the trailer B+ charging wire is hot all the time. Did GM leave us a nice easy way to change that to be switched with key on?

Edited June 29, 2023 by Z1500

[64BAwagon]

I believe this circuit is controlled by the management system and will disconnect once the battery reaches a certain threshold. 

On my 2005 HD the trailer 12v+ was constant on and that truck didnt have the rundown protection. I wired a relay to feed the circuit and triggered it to an ignition source. That way the circuit was only connected when the truck was running thereby isolating the trailer from the truck when we stopped.