i have put a cable in my clk 350,whats wrong TIA

[mercman111]

i have put a cable in my car glovebox,its an aux cable to usb but does not work, whats wrong,i was using a usb connector to a usb dongle, TIA

 

[Blobcat]

i have put a cable in my car glovebox,its an aux cable to usb but does not work, whats wrong,i was using a usb connector to a usb dongle, TIA

What are you selecting on the head unit?
I had to change from media to aux when I went from my iPod interface lead to the lead for my DAB

 

[mercman111]

i have tried that,im going from aux lead to a usb dongle