iPhone iPad not playing through stereo anymore

[user-removed]

Hi, I have a USB port on my car stereo which has worked fine to play spotify through until recently. Now it only plays through the speakers on the iPhone 5/iPad mini itself with the USB plugged in. The stereo recognizes the USB as it used to but sound comes not from car but from built in speakers on the devices. I've changed USB cord. Any thoughts? It used to work that's what's so frustrating!
Thank you

[MichaelJerzak]

have you tried a clean reinstallation as explained here http://community.spotify.com/t5/Help-iOS-iPhone-iPad-iPod-Touch/iOS-Troubleshooting-Spotify/td-p/105...

[user-removed]

Thank you. Tried this and did not work. In a.m., I will reset stereo in same vane. Thanks mike!

[user-removed]

In case anyone else is having this issue, I'll update as I try things.  Reset car stereo with no change in problem.  Also tried playing itunes song and stream radio, neither of which go through stereo now.  Again, radio recognizes usb, audio comes from iphone/ipad speakers instead of car speakers.  Used multiple cords too.