Everything works from the buttons, if its not the buttons then its in the wire harness going to the buttons.
It could be 2 stray frayed wires in the harness right in back of the button assembly.
I would first check at the back of the plug that plugs into the button assembly, (the group of wires that plugs into the back of the buttons) pull back some of the plastic tape to see if any of the wires are bare. look for a bare wire or wires that are melted together. (sometimes all it takes is one single strand touching another)
The other place it might be is where the wires pass through the door, (at the door jamb), opening and closing the door may have pulled wires or caused them to fray.
For this you have to dig deeper into the door to get at it, this would require removing the inside door panel to get at the wire harness to get a look at it.
Last edited by beeguz; 06-15-2017 at 10:07 AM.