Mercury - Trim Adapter (8-Pin to 3-Pin) Trim Harness Converter 84-8M0163380. OverviewThis adapter gives you a simple way to connect a 3-pin trim switch or trim device to an 8-pin trim harness. It's a small plug-in piece that saves you from cutting wires or trying to build your own jumper. If you're mixing older trim parts with newer rigging-or you're adding a trim switch that doesn't match the existing connector-this adapter keeps the wiring clean and makes the trim function behave the way it sh