I think he's wanting to swap in the EATC system from an Explorer. Electronic Automatic Temperature Control. None of the Rangers came with it. I could have sworn that there was a write up on it around here once upon a time. Memory says that Rwenzing (not sure I have that spelled right) did a writeup about it back in the day, but I could be remembering something from RPS or one of the other forums back then.
I never paid much attention to the swap myself. More complex than I wanted in AC controls, and IIRC it had a minimum temperature which I didn't want. I think the minimum temp was in the 60s. If it's 50 degrees out and I want the AC on, I want the damn AC on.
Anyhow if OP will search Explorer EATC swap he might find what he's looking for somewhere. It's often referred to by those initials and might help weed out some of the results.