08M66-ZW7-025AH 17 Cnd 25' Main Harn - Overview. The 08M66-ZW7-025AH 17 Cnd 25' Main Harn is a genuine OEM 25-foot wiring harness designed for Honda marine engine systems. Serving as the central conduit for electrical connections, it supports the marine engine's key operational systems. Crafted to meet factory specifications, this main harness ensures seamless integration with existing parts, maintaining optimal performance and durability in demanding marine environments.. Key Features. 17-wire