So, interesting developments tonight... Not only did I have to rescue my friend's trailer from a soft, muddy yard, his truck (2WD) got stuck as well. Do you need 4x4? Nope. Until you do... I've only had 4x4 and always will.
Hook up to his trailer, and to my dismay, all lights work, but truck won't recognize it. No brakes. At this point I had accepted my fate and was going to have the dealer look at and potentially replace brake controller. After getting both of them unstuck, I pulled the camper a couple of miles down the road. There, I kept messing with the connector, but nothing worked. Pins looked all good, we had die-electric grease on them, all seemed well. On a whim, I decided to move the 7 pin connector pins on my truck around. Pinched them towards the center, pinched center pins closer, etc. Plugged his camper back in, cranked up truck and the darn thing came to life! What the?
I didn't have time to go see if this fixed my camper braking issues, but if that was it, I'd be amazingly relieved, but also frustrated and ashamed of the fact that I didn't think of it at first, and ashamed of all the time I've made all of you waste (but am SO thankful for all the knowledge shared). I'm still not out of the woods, but I'm hopeful...