TuffMudder,
In regards to the compressor I pulled everything. It'll either be going in the Tundra or whatever I get to replace the 80.
Concerning the rear locker,
This is conjecture from conversations in person with ACC, but I did have them take a look at it while they HG and front axle were getting rebuilt. Of course this is all external without taking apart the 3rd member, but both Mike and Dugan (owners) felt it was most like the actuator itself. It was getting power after they re-wired it and I guess there's a way (getting out of my knowledge level) they can see if there actuator is engaging or not. Dugan didn't think the actuator was engaging.
At the time he recommended just a rebuild of the actuator, but after spending $6,ooo bucks at the time it was low on my priority list.
Prior to all of this I engaged the lockers frequently to keep them from sticking, they always worked flawlessly on the trail. The stupid mistake I make was cutting the exhaust in front of the rear axle which burned the wiring loom to the locker.

. Rookie mistake. The other mistake I made was not getting it looked at until probably 3 years later (as mentioned above at ACC). SO the locker went at least a full 3 years without being engaged which is why I think it's merely stuck.
A lot to read to answer a simple question, but like many others in this group, I've tried my best to maintain this truck as a wheeler and DD for 11 years with intention to keep it for even longer.