Also check behind the back seat. Pull the cover off and check connections to amp. I had a similar issue and found the usb connection came apart causing no audio
I used a PAC amppro, AP4-FD31 to work a aftermarket system. Should work with your vehicle. I put in a focal component set up front, alpine coax in the rear, and a kicker sub under rear seats, all driven by an alpine 5 channels amp. Sounds fantastic. Good luck
Go to youtube and you will find a plethora of info on this subject. Provo beast is a good site. I did my own, Focal flax and K2 tweeters up front alpine coax in rear, and kicker down firing sub under rear seat and to round it out alpine 5 channels amp. Sounds amazing, good luck