Irecently purchaseda 1991 Mercedes 420SEL and it came with afactory Mercedes Benz radio whenI turn the radio on all it does is flash "wait" no matter what I do thats all it does. I think the radio in it isnot original because when Iremoved it to try a different oneout of a my 1988 420SELit was not thesame wiring. Also it has a 10 disk cd changerand I am thinking the one that came with it is not compatable with the cd changer. Or is there aanti-theft security code that needs to be reset? Any help would begreatly appreciated. I have also noticed that theCD changer sounds like its shuffling disk continusly, it doesnt stop until I pull thecd holder out.