Mercury - Ignition Harness Non-DTS 14-Pin Engine Ignition and Gauge Wiring 84-896537T29. The Mercury Non-DTS Ignition Harness is designed for mechanical control setups where the helm is positioned far forward and standard harness lengths do not reach cleanly. It is commonly used on larger boats that require a single, uninterrupted wiring run instead of stacking multiple extensions. The 29-foot length allows the harness to route naturally through rigging channels without tension, tight bends, or