No sound from rear speakers ...
 

Today I've desovered that only front speakers are working in my car, but there are 3 more speakers (2 in rear doors and one in trunk) which are not working. I have a VXL Korean version of Veracruz (everything is included). First I want to understand possible reasons of my issue and if it's a serious problem then I'll try to contact with domestic AS. Can anybody give a suggestion on how to fix or some advice - where an amplfier is located and what could be a reason for my issue?

Is the fader control set to 100% forward?

No, I've played with that control and it's seem like rear speakers just doesn't work.

Dealer ... warranty ... problem solved.

Unfortunately, my warranty is already expired and I'm afraid that dealer will propose to change Amplifier and Media system for n'th K$ without any attempt to understand the reason of the problem...