I have the exact same issue. I cannot get auto on Pin 3. I have the adapter working to key up the mic but I cannot seem to get it to pass audio it is receiving. I tried grounding Pin 1 and they didnt work. Right now I have 1-GND,2-PTT, 3-SPK,5-GND,7-Mic-HI,10-GND. I am scratching my head...