I own a 1992 Mercedes 300se. This car sat in a garage for about 2 and a half years before I got to it. There are several problems that I am attempting to fix. First things first, I need a radio in my car!! I waited for the 'wait' on the radio display to turn into 'code' and it took the code in fine. But, it still doesnt work! I now get an 'E 3' error code when I turn it on. I went to the delear and they said either something has to be replaced or that cd changer wiring is bad. In an attempt to get the radio working I unplugged the cd changer. Now, i get an 'E 2' error code. I need some help. The dealrship also said that the problem could have been caused by the fact that the battery has not been connected to the car for a long period of time. He claimed that there is a "mini-battery" type thing that the radio uses that has died due to lack of power. I have located the 2 other peices of the radio in the trunk passanger side of the car behind the panneling. I dont know what to do now. The dealership requests too much money from me. I went to purchase a new radio receiver but the electronics store told me that the cd changer in the trunk may not work if I install it. So i'm stuck! The CD changer in the trunk is the becker silverstone 980 10-disc model. And the radio receiver is a becker silverstone grand prix, I beleive. I trully do not know what to do now, anyeone with any experiance on how to help me or advice please reply. Thank you very much for your patience in reading this message and if you can help me, I thank you in advance.