I recently bought a 2006 320SDA with Mercury’s SystemView SC5000. When I bought it I noticed that the speedo (both dash unit and speed in SC5000) wasn’t working (probably a bad paddle wheel as the SC5000 shows ‘none’ in the speed section where it should display paddle/pitot/GPS) I really haven’t put much thought into it as I figured that boat speedos are inherently inaccurate anyway and the boat is equipped with a Garmin 740s GPS and I can get speed data from there. Now that fall is rolling around I’m looking for projects to do on the boat. I understand that the GPS can be connected to the SC5000 via NMEA 0813. I pulled the panel tonight to look at the harness for my SC5000 and I found the blue/white wires. They are attached to a harness/plug. The NMEA 0813 connections from my garmin has no harness. Is this a piece that I need to buy or am I OK splicing the wires into the blue/white wires from the SC5000? Anyone do this? Can you post pics of your connections?