Wells VR603 Voltage Regulator Voltage regulators control the charging voltage that the alternator produces, commonly keeping it between 13.5 and 14.5 V to protect the electrical components throughout the vehicle When not replaced, the battery will discharge or overcharge (destroying battery), engine will die, CEL will illuminate, charging system light will illuminate, or alternator damage may occur Designed to meet or exceed OE specifications in form, fit, and function Global coverage for import and/or domestic applications