I have a 2004 Silverado Z71 crew cab, and also a young son. We have always had the "safety" lock on the back doors so that they cannot be opened from the inside. This weekend we were going somewhere without the boy, and an adult was riding in the back seat, and it was a pain to have to keep opening the door for them. I turned off the "safety" lock so that one door could be opened from the inside, but then noticed that the door would no longer lock....AT ALL. The other doors lock/unlock just fine with both the remote fob and manually hitting the power lock button or sliding the manual lock back and forth. This one door seems to be "stuck" unlocked. I cannot even lock it manually, since it refuses to move. Since I can't lock it manually, I don't THINK it's an electrical issue, but then again I'm certainly no expert. Any ideas on what the problem is? I'd prefer to fix it myself if it's something easy, but if it's involved I will have to take it in somewhere tomorrow because I don't want to leave my truck sitting around with one door essentially unlocked all the time. We have had issues at my work with cars being broken into. I don't want someone ransacking my truck, even if the alarm does go off when the unlocked door is opened. Any tips would be appreciated! Thanks!