89 Sable Tailgate

My 89 sable wagon has a problem. When i put the key in the tailgate lock, it doesnt turn either left or right. So...i can neither open the back window or the tailgate itself. Frustrating...

I was hoping someone could tell me if this lock is strictly a mechanical device or if it is in fact a power lock. I checked the fuse setup in my user manual and made sure they were all present and accounted for in the fuse box...all seems fine. Thanks in advance for any light you can shed.

Is the temp dropping so low that the lock is freezing? Try warming your key. Have you tried a different key (maybe the one you are trying is worn out)? Try spraying the lock with WD-40 to clean and free up the tumblers.