I have a 1998 mercedes benz c280. While driving all of the power started draining. Lights started blinking, the headlights dimmed, the door locks stopped working, windows stopped working, cd player shut off. And eventually the car stopped moving and shut down. I had the battery checked and it was bad so I got a new one but the problem continued. I also took the alternator in to get tested and it is fine, and I also checked some of the fuses. So what else could be wrong with it?