My tahoe has bose but no onstar. I bought the gmos04 harness. All the speakers are wired correctly. We have no sound. Do I need to connect the blue/white wire on the RCA harness to the blue/white wire on the gmos04? Also the mute wire on the RCA harness is yellow/black, do I need to connect that to the parking wire and ground wire or can I just ground it by its self? There is a brown mute wire on the gmos04 harness, do I need to connect that to the yellow/black mute or just leave it be. Sorry for the bad gramar. Any help would be awesome thanks.