I started my S4 this morning and the battery seemed a little bit weak. It didn't just turn over like normal. I had been noticing this over the past week or so. The battery must be loosing some power over nght. After it started this morning the radio would not play and the display only reads 'safe'. The display in the gauge cluster is blank. Even after stopping the car a few times and starting again, still 'safe'. Is this a theft deterrent type of thing, where I just have to enter a code to get the radio to work? Maybe the radio detected no power and is acting like the HU was removed. Any ideas? BTW the volt meter reads just over 14 volts, so I'm pretty sure, I don't have an alternator problem.