Hello ladies and gentlemen, I've been lurking here for a few weeks since I got my 300SDL, and figured it was about time to post. I wired in a new Sony headunit to my car, with one problem. Since the install, the dome light only comes on with the key in the ignition, and the radio only works with key on and the door open. I searched, and found someone with a similar problem, traced back to the Power Seat Diode. I went to Radio Shack today and purchased a replacement 1N4003 diode, and soldered it into the factory holder in the fuse box. Popped it in hoping to hear the radio turn on. No such luck. I'm now out of ideas... seems the factory diode was working just fine. Any ideas?