Mercury Remote Control Adapter Harness 892473A01. Overview. This remote control adapter harness is used when updating or converting older Mercury ignition and control wiring to a newer setup. It's a simple bridge piece that lets different connector styles communicate without cutting or modifying the boat's wiring. Most techs use it during repowers or control upgrades where the engine and helm hardware are from different generations. It keeps the job clean and avoids guesswork at the dash.. Key F