Jose, as you know your inside locks will work by pushing the door handle forward... then as you also know, you just pull it backwards to unlock. But the lock on the outside is a different mechanism inside. It operates seperately from the inside mechanism. So if you lock the door from the inside you MUST unlock it from the inside as well. The saem with the outside lock. It MUST be unlocked from the outside.
I had problems with my pass side inside lock to begin with so couldn't lock my truck at all (no key on driver's side), When I put keyed locks on both sides I removed the little lock tab on the mechanism so I now can't lock it from the inside at all... only the outside. No biggie, I just have to walk around the truck and lock it outside.
If you pulll the lock mechanism out of the door and play with it, it's pretty apparent how the locks work.
Hope this helps!
