Mercury - Ignition Harness Non-DTS 14-Pin Engine Ignition and Gauge Wiring 84-896537T40. The Mercury Non-DTS Ignition Harness is designed for mechanical control systems that require a long, uninterrupted wiring run between the helm and the engine. It is commonly used on larger boats with forward-mounted consoles where shorter harnesses are not practical. The 40-foot length allows wiring to route cleanly through rigging channels without tension, sharp bends, or the need for stacked extensions.. U