Hi, I just picked up a 1991 420SEL. I need to ask a couple of questions. This car sat for four years. The previous owner did a pro tune-up before parking the car and believed everything was in good order. When I bought the car the battery was dead. After putting in a new battery the car started and drives. Problem 1. The radio/ CD does not come on... are there start-up codes for these becker stereos and how do I find them? Problem 2. The car idles at 2K in park but runs fine under a load in drive? Has anybody had these problems? And can you help with some advice. Thanks in advance.