Mercury - Dual Remote Control Wiring Harness Kit Ignition and Engine Set 84-896537K30. The Mercury Dual Remote Control Wiring Harness Kit is designed for boats equipped with twin outboards operated from a single helm. This matched harness set provides equal-length wiring runs so both engines receive consistent ignition and engine signals. Using a dedicated dual-harness kit helps keep wiring organized behind the console and avoids mixing harness lengths or adding unnecessary extensions.. Balanced