I had the same problem here, try this:
unplug your phone from the AV adapter turn off the bluetooth on your iPhone with a pen or sharp object, press the reset button on the botton left of the screen for 10 seconds go to the config screen and change to iPhone AV (before reconnecting the bluetooth and AV adapter) turn bluetooth on connect AV adapter enjoy!
If this does'l work repeat the process.
regards from Brazil
Jota Stroeter