Should I assume that since all four speakers went at once that it is a radio problem. I even went and purchased a OEM radio and hooked it up and got the same results. I guess I'm just unlucky.
Here is the description of your speaker system; this tells me that the front speakers have an amp built in each; there is a ''radio choke relay'' that powers both front speakers! Here is the component location, for the relay, and then the wiring to it and the speakers. You could pull a door panel, and check for 12v and ground, at a front speaker, on the wires shown; if OK, then the speakers are bad. If no 12v, then it is in the choke relay.
Is the choke relay a factory part or can it be purchased elsewhere. Also where is it located on the truck?