Mercury - Quad Engine Instrument Adapter Shared Gauge Power Link 84-898284T01. Overview. On quad-engine boats, keeping gauge power simple can be a challenge. The Mercury 84-898284T01 Quad Engine Instrument Adapter takes the guesswork out of it by letting SmartCraft gauges power up from any of the four key switches. Whether the port engine comes online first or the starboard pair fires up together, the gauges wake cleanly and in sync. It keeps the helm predictable and avoids the wiring clutter th