35673-ZW5-003 Water Temp Sensor - Overview. The 35673-ZW5-003 Water Temp Sensor is a critical component in Honda marine engine systems. It monitors the engine's coolant temperature and sends vital information to the boat's control system for accurate engine temperature regulation. This ensures the engine operates within safe thermal limits, preventing overheating and maintaining reliable performance. Designed specifically for Honda marine engines, it ensures seamless integration with existing pa