Mercury - 3-Pin Extension Harness (20 ft) Rigging Accessory 84-8M0191746. OverviewThis 20-foot extension harness gives you the extra reach needed to run the steering 3-pin lead from the rig center breakout to the electric steering actuator. It's mainly for boats where the wiring path takes the long way around or the actuator sits farther back than usual. Each actuator uses its own harness so the wiring stays relaxed instead of stretched. With the extra length, routing is easier and the steering