power locks

I'm having a problem with one of the power locks on my truck. when i hit the power lock button to lock the doors, only the passenger side door locks. The lock on the driver side will not move down to lock. I am not even able to force it down with my hand. Anybody have any idea what the problems is?? I'm not liking the idea of leaving my truck unlocked all the time.

Look inside the door, I bet the linkage is jammed up somewhere... maybe the motor's bad, but I don't see how that could cause the lock to completely freeze up.

Sounds like your lock actuator. I've never replaced one on one of these trucks but I've done lots of others and they were all pretty simple.