I doubt that the wiring is bad if you havent touched them and that they were working. If you have a digital multimeter check if you have current coming back to those speakers when the radio is on. If you dont then I would first suspect the radio, but if you have long enough leads on the multi meter then do a resestance test on the wires in the harness and going back to the rear speakers. But since they are both not working it is most likely your deck and it should be replaced, anything else spliced and hob jobbed together would sound bad. You can get a cheap deck if you dont want all the fancy controls for under 100 bucks. Good Luck in the investigation.