The car is a 1994 C280 w202 which I purchased about 6 weeks ago.the stereo is factory and on buying the car it was not working. Further investigation proved that it was the amplifier in the boot/trunk that was faulty and has been by-passed so the head unit now works. I have decided to replace the head unit with no frills standard unit which by chance has a european double connector on it so no need for a harness connector. The make is "American HI-FI" There is no provision on it however for the plug which goes to the amplifier. At present the stereo is just sitting in there with the plug attached but doesnt appear to have any power and will not switch on hence no sound and the antenna does not power up. Does it require a power source from the amplifier connection or elsewhere. Your help would be appreciated