31238-ZV4-812 Terminal Unit - Overview. The 31238-ZV4-812 Terminal Unit is an essential component within Honda marine engine electrical systems. It serves as a critical junction point facilitating the run and transfer of electrical signals and power among various parts in the marine engine's starter motor system. Designed to support electrical integration and communication, it ensures dependable and consistent engine operation.. Key Features. Genuine OEM Honda component guaranteeing factory-grad