Modified USB headset connector

[Vavavoom]

Dear all,

I just spent hours modifying the original usb connector taken from the headset. My aim was to modify it to charge the hermes while connected to my car stereo. I managed to open the connector and solder on two extra cables for charging. My problem now is that the phone doesn't recognise the headset any-more.

So here my question: how does the phone recognise that the headset is connected? Do I need to bridge any connections (e.g. on the usb data side etc.) for the phone to switch from internal loudspeaker to output throught the connector? Any help greatly appreciated.

Thanks, Ralf