04 Sonata radio...help
 

So I installed a new stereo. Soldered all the wires and plugged it in. It works fine… except there is no sound. I connect an outside speaker to the head unit any music came out. I have since installed the old radio back in the car, so the speakers are fine. I think there might be a stock amplifier inside the car I might have to wire around. Is anyone familiar with this? Where is it located in the car? Any other thing that could be wrong with it? This was supposed to take an hour; it’s been a week so far. Please Help

Make sure all of the blue wires (blue, blue/white) are all tied together, assuming you used a plug for the car side of the harness. Those would be your amp turn-ons/power antennas.

Yes, I think so too, please check all the cables.