Lock Wont Latch When Truck Is On

I have a 2001 with a funky driver's side lock (electric)

The key can unlock the door but cannot lock it, I can still lock it manually and by the button. The tricky part is that the button only locks the doors when the truck is completely off, if I have the key turned to ACC or START, the button will engage the locks but not latch. The passenger's side is doing the same thing when the truck is on but the key works just fine

 

This part is by design, it's to keep you from acidentally locking your keys in the truck. Pretty much every vehicle since the late 90s with power locks will not allow the doors to be locked with the key in the ignition.

As for the key lock on the door not working your gona have to pull the door panel off and have a look at what's going on between the key cylinder and door latch.