It is nice to see another G5 in the mix. I am building out a 2011 G5 HC, and my build thread in the Short Bus Conversion sub-forum.
I have a copy of my bus' wiring diagrams, I can email to you if you PM your email address. The diagrams may work for your bus too. If all else fails, you could contact Girardin in Quebec and ask them if they could send you a copy based on your VIN.
Looking forward to seeing your build!
Have a great weekend!