Does your truck have a Key FOB? And does it work? I have not had problems with the locks on my Excursion, but I did have an issue with a previous Suburban. The door lock buttons did not work, but the Key FOB did. I found that the door switch panel was not getting power. I ran a new power line to the Drivers door and into the proper connector on the door lock switch and all was fine. Never had another problem. So, in your case, I would check to see if your door switch is getting and power...