I would have to say this has been the most challanging part of the build to date. Over the last 3 months, I have individually wired each system and tested. There has been much time spent on emailing & researching the vendors instructions, planning & checking of systems. The primary systems are. Trutrak AP IV, which can be switched to an EMS Trutrak GP, which can be switched to an EMS as backup PFI/EMS Garmin GNS 430W - Slaved to AP Garmin 695 - Slaved to AP switched with 430 Garmin SL30 NAV COM Garmin GMA 347 Garmin GTX327 Trutrak ADI With GPS Alpha Systems AOA EXP Bus Electrical Panel & Indicator G3 Ignition System Approach Fast Stack Wiring Bus