35490-ZW5-003 Oil Pressure Switch - Overview. The 35490-ZW5-003 Oil Pressure Switch is a crucial component in Honda marine engine systems. This switch monitors the oil pressure within the engine's lubrication system, ensuring that the engine operates safely and efficiently. It plays a vital role by sending electrical signals to alert the operator when oil pressure falls below a designated safe level, preventing potential engine damage. The 35490-ZW5-003 is engineered to seamlessly integrate with