31710-ZY3-003 Rectifier Assembly - Overview. The 31710-ZY3-003 Rectifier Assembly is a critical component in Honda marine engine electrical systems. This valuable part converts the raw alternating current (AC) produced by the engine's alternator into direct current (DC) power. This DC power is necessary to charge the boat's battery and operate essential electrical components with consistent performance. Engineered as a genuine Honda OEM component, it guarantees perfect fit and optimal reliabilit