Project I have been working on. Just had to figure out the refresh BCM. The black BCM module closest to the firewall has pin #1 open for adding accessory lights. I used a set of 60" MICTUNING cargo led strips.
The black connector is a pain to get out. It is in close quarters to the firewall and hard to see. There is a locking tab that must be released first then you push in on the release tab. I used a factory molex connector (shout out to @64BAwagon) in pin #1 and tied it to the hot side of the led light strips after cutting out the supplied switch. By hooking these up in this the lights fade on and off with the interior lights.
After buying my new Denali 3500 I realized my current B&W tow & stow was under rated (14500) For those that have an older B&W tow and stow you should be aware of this. I did contact B&W and asked about their current offering which is rated at 18500 lbs. They said if I provided a picture of my current hitch cut in half they would sell me a new updated one for $299. I declined as I am giving my old one to my son in-law.
I realize I am late to the discussion, but I am using the Bulletproff hitch lock and Infinite rule locking hitch pins. I had the same issue as you with the locking hitch pins (Bulletproff) not fitting. I called Infinite rule and they said B&W's holes are slightly undersized, probably due to powder coating. I ordered 3 pins from them and the fit perfectly.
Ok K9 Body Control Module X8 Gray which is closest to the firewall shows pins 1&2 are open. Based of of what you are saying and info in the foot well lights thread I should be able to use a molex pin and accomplish what I want without using a posi-tap on the LCM?
So by looking at GMUPFITTER,COM it appears the 24's have a LCM lighting control module as well as the BCM, I think I have it narrowed down K219 LCM X5 pin 1, approach lamp control.
So I am installing running board lights on my 2024 Denali 3500. I did this same mode on my 2021 SLT 2500 using the puddle lamps to trigger them. I noticed the BCM modules are different on the 24's . On the 21 module 7 pin 8 was for the puddle lamps. Not sure it is the same on the 24's. Does anyone have the BCM layout for the 24's? My other option is to use the cargo lamps in the bed of the truck as the trigger. Only issue there is I have heard some people state the lights will blink about 3 time before coming on, and I don't want that.