Mercury - Next-Gen ERC Extension Harness Kit (Triple) 5-Foot Extension 98-8M0173754. OverviewThis five-foot extension gives a triple-engine Next-Gen ERC setup the extra slack it usually needs when space behind the helm gets tight. Triple-engine boats often have longer or more awkward rigging paths, and this harness keeps you from forcing sharp bends or stretching the wiring. It lets everything run in a cleaner, more natural line, which makes the controls feel steadier. It's a small add-on that t