31750-ZY1-003 Regulator Rectifier - Overview. The 31750-ZY1-003 Regulator Rectifier is an essential electrical component dedicated to the regulation and conversion of electrical current within Honda marine engine systems. This integral part operates within the engine's electrical system, where it converts alternating current (AC) generated by the stator into direct current (DC) and regulates the voltage output to charge the battery while powering the boat's onboard electrical components. Designe