Mercury - Lower Dual Helm Harness Quad Engine Next Gen DTS Helm Harness 84-8M0157220. OverviewThis harness handles the lower helm on a quad-engine, dual-station DTS setup. It gives the lower station a clean, direct path into the system so it isn't sharing tight wiring space with the upper helm. Once the upper harness and the helm-to-helm extensions are added, both stations stay in sync without the controls feeling jittery or delayed. It's a simple piece, but it keeps a big multi-engine layout fr