nissan murano dvd no sound

Ok guys I was switching radios on a nissan murano 2005 because the cd was not reading (same radio because this is a dealer) and when i switched the first radio it didnt work either (was the same problem cd not reading), so i made a reset,  i disconnected the ground batt. wire then i connected again and the same problem, after this i try with another radio this one works very good but now i don't have audio when i play the dvd. i rechecked the wires and it looks good, I mean ,didnt touch anything else than the radio connectors (unplug-plug), I checked the audio and video wires but it seems that there is not an fm modulator. The owner told me that  the dvd audio was working wen he put in to FM 88.5   What should i do now?

please help me Thank you!