TK30 - How come I can't hear my iPod, USB or Bluetooth music through my speakers?

a) If you have enabled the Line-Out setting on the TK30, you must ensure that you have selected the appropriate source on your vehicle's entertainment system for TK30 music playback (typically the Auxilliary input).  

b) Also, ensure that the RCA connections from the TK30 are connected to the audio input of your vehicle's entertainment system (or appropriate adapter).  

c) Also, ensure that the volume level on your media device is turned up.  If you are not using an Auxilliary input of your vehicle's entertainment system for TK30 music playback, ensure that the Line-Out setting is disabled.