you consider a car's powerplant to be its heart, then the electrical system would be its central nervous system. Like any central nervous system, the car's electrical system controls nearly every aspect of a car's operation. From the engine firing sequence and climate control system to the car's electronic safety system, they're all heavily dependent on the reliable operation of the car's electrical system. As modern cars grow more sophisticated with even more electronics than before, the stability and reliability of a car's electrical systems gains even more importance.