Mercury - Harness-TVM w/RC - 84-8M0205807. The Mercury Harness-TVM w/RC - 84-8M0205807 is a genuine OEM wiring harness designed for use with Mercury Total Vessel Management (TVM) systems. Built to deliver seamless signal routing and control, this harness ensures optimal integration between your helm controls and engine electronics, enabling smooth vessel operation and enhanced performance monitoring.. Key Features. OEM Precision Fit - Manufactured to Mercury specifications for reliable plug-and-