My 99 will not unlock regularly and you can not open the door or unlock it manually. You must unlock it repeatedly until it goes. Pulled the panel and all seems ok so... Potentially dangerous as you cant open the door from the inside either.
I believe you are saying that it is difficult to unlock the door. When the door is unlocked the outside and inside handles work as normal. When you had the panel off everything else was in proper place (ie lock actuator isnt busted loose from the rivet and sitting sideways or dangling, rods are all connected). Is this correct?
If so, your problem is either the operating rod that goes from the latch to the door handle, the actuator, or the latch itself.
I suggest you start by pulling the inside panel and try locking/unlocking while pushing up on the operating rod. If that works then you likely have the floppy handle/return spring problem or one of the plastic rod attachments are broken. This is a very common repair. Fixes such as replacing the handle/springs, using a helper spring, or replacing plastic tabs are well covered in the forum search & stickies.
If the operating rod makes no difference, next try disconnecting the power lock actuator to see if you can lock by key. Normally a damaged lock cylinder doesnt bind the rest of the mechanism so if it turns easily locking/unlocking without the actuator then you know what to replace.
If no luck with the first two, you'll need to remove the latch itself. There are springs in the latch which can break leading to this problem, especially if a broken piece gets lodged. I've seen write-ups on how to repair a latch, but personally I've only replace the unit without having taken one apart so you'll need to do some searching to find instructions.
