Ok this is the OP posting just in case someone searches for this thread in the future.
The black box pictured in post 3 of this thread is the connections for the trailer/toad 7 pin connector. It’s labeled Arens and has 4 screws that hold the cover on. The screws stay attached to the cover so you don’t drop them. The box is in the passenger side compartment just behind the rear wheels. In the 08 Discovery 40x.
Thanks for all the help!
Side note, the fuses were blown when the center connector, which wasn’t being used, came loose and was rattling around inside the Pollak connection. Yep, I blew one of the new fuses right off the bat!
Tim & Mary Discovery 40X. Chevy Tahoe. RVM32
"I've been lost now, days uncounted..."GFR"