necompressor

Hello, I am trying to swap my vert radio with another 88 vert radio. All I get when I power it up is the radio station indicator - no sound at all, or power to the headrest speakers. Any suggestions? If I give up and go aftermarket, are there any kits available for a double din set up that look good? (ie - I'd use a kenwood md player with a separate cd/spectrum analyzier. Also, is it possible to use the factory headrest speakers and amplifier with an aftermarket system and if yes, how? thanks Eric