I have a 1999 ford explorer sport. I have always had a bit of difficulty with the locks, but it has always worked. Recently, The driver's side door lock will not turn all the way to unlock itself, though it will unlock everything else with the power lock system. It almost feels like its getting stuck on something but I don't know how to check that. If I pull the handle on the inside, after about 2 pulls, it'll open, but otherwise no. The outside handle feels much looser than it used to as well. I can also sometimes get the outside lock to open if the door isn't closed. What could this be? Is this something I will have to completely replace the lock for? And if I do have to replace the lock, does that mean getting a new key made with the electronics part that makes it skyrocket in cost?