I have a 2003 F250 4x4 and I can't seem to find out why it is beeping. It's the same tone as if you killed the vehicle and left the lights on, but beeps continuously when all doors are closed and the lights are off. It stops when you open a door or crank the truck. When you leave the vehicle and come back, it's still beeping. I want to try and stop this before it drains my battery and/or causes more problems.