I installed a JVC kw-av61 headunit in my truck. when I hook up my ipod touch 4th gen through the USB jack it won't play music. It syncs to the ipod, but it won't play any sound. It shows thar it is playing a song, but no sound.

 

Unless I'm reading the compatabillity chart wrong: http://www3.jvckenwood.com/english/car/ipod/ipod_models.html

It looks like you need a special cable for your headunit to work with any iPod, see note number 18 below the table.

If you have that cable and it's not working, you'll probably need to contact jvc and troubleshoot with them to see if you need to return a defective unit.

If I am reading that chart wrong some other things to try include making sure the iPod's firmware is fully up to date, power cycling the iPod, and finally going through the owners manual of the head unit again to make sure there's no special setting you need to turn on.

 

Well... after constant fiddling with my headunit, I finally got it to work. The JVC owners manual told me to do it one way, and it didn't work that way. So I did it a different way and it now works perfectly. You may be right about needing a special cable to have it work the way the owners manual says, but with the way I did it I won't have to spend any money to get it to work. But I do thank you pizzaman711 very much for your helpful research and advice