12. If it has sound, please neglect the following step; if it has no sound,please connect the“AUDIO OUT”wire on main cable to AUX hole in car.
Check again if it has sound or not, power off car if sound is available.
11. If it has sound, no need to check next step, if no sound, please connect "Audio out"cable into AUX input,check sound again and power off unit if has sound.