Here is a two part question question for anyone out there that wants to take a try at this one. I have a pair of 2002 Yamaha 200 HP HPDI eninges with dual digital tach, digital spedo, and fuel management.First off I am curious what each wire does at the rear of the guages. I know that blue is the backlighting and I removed this wire from the harness and hooked it to the nav light switch so that when the nav lights are on, so is the guage lights - makes sense to me. So what are the Green, Yellow, and Red wires for. I noted on the rigging guide that there is no red wire to the port tach. Black must be ground. I think Green is the tach signal?? Please define these for me.Now for the second part of my question. My fuel management only works with the Starboard engine switch on. This is fine with both engines running or when trolling with the starboard engine, but when I troll with the port engine I dont get any fuel managment info including loosing whatever fuel is burt not being included in my "total used". If possible, I want to change the rigging so that I get fuel management single engine and with both so that I get more accurate fuel mangement while single engine trolling.