Transfer case center diff lock won’t engage

[TSICU]

Hey everyone, I’ve got an 04 GX 470 that I recently did a t-case swap on. Long story short, the old case had the common problem of leaking at the o-ring seal and the thing was dry when I got it from the dealer. That, or they just didn’t refill the case when they drained it. Regardless, it damaged the case and I swapped it with a used one in my garage. 
 

However, now the center diff won’t lock on the new case. I’ve read around that if there’s oil in the actuator the thing can’t engage correctly. It’s also possible that it sat for a long time and froze. I still have the old functioning actuator. Do you think the car has to relearn how to lock it since it was disconnected, or is it a faulty actuator? 
 

Thanks!