Mercury - 3-Pin Extension Harness (5 ft) Rigging Accessory 84-8M0191743. OverviewThis 5-foot extension harness gives you just a bit more reach between the rig center's 3-pin steering breakout and the electric steering actuator. It's helpful when the original lead comes up short or when you want a cleaner, gentler wiring path. Each actuator uses its own harness, which keeps the wiring relaxed instead of stretched tight. With a smoother run, steering often feels more settled during slow maneuvers.