Ok, I've made some progress in replacing the head unit in my '98 328is (HK sound system) with the Empeg MKII but have a question about the connector. I bought an BMW connector adaptor and carefully matched the wiring to the Empeg ISO adaptor. Unfortunately, I get no sound. I did notice another white connector (12-pin) that connected to the original head unit but was that just for the CD changer (I used to have one) or is it an additional connector to the HK amp? Also, will the line level output from the Empeg match the 5v input I believe is required by the Harmon Kardon amp?

Thanks,
David