I cannot hear the radio through the actual speakers?

Ok, so my 01 tahoe has a working radio and working speakers. I have a center console, and the rear of the console has radio control, with headphone jacks. The radio itself appears to work, can change stations, time, etc. And also the rear audio jack works (If I plug in headphones I can hear the radio). The problem is, I cannot hear the radio through the actual speakers. I tested two of the speakers, and the stock sub, and they all work. I have also fiddled with the headphone jack to make sure it wasn't "stuck" in that head phone mode, and I'm pretty sure that isn't it. I've pulled out the radio itself and unplugged it. No faulty wires (as far as I could tell). I did however, try something. There is 3 "cables" that go in to the back of the Delco radio. 1 is the actual antenna wire, and the other are wire harnesses (one big, one small). I don't know which goes to which, but I unplugged the small harness, and the radio was still working, as well as the rear audio jack. So could it be the small harness that works the door speakers? I don't know. Anyway, that's all I have checked. I've spent 5+ hours trying to get the speakers to work, but they wont do it. It isnt a fuse btw, I checked them all. Thanks for reading, and if you guys have ANY solutions, please let me know. Thanks, Logan