All HDX connections need to be wired together on the same pin number. I called Dynon tech support and they said this is because either of the dual HDXs can be the Primary Flight Display depending on the order in which they boot up. Only the primary will communicate with the other avionincs. So, both displays should be wired together so that either can be the primary.
I bought the Dynon HDX harness for the pilot side, but because of the way the screens must be wired together, buying the harness for the copilot side would not save any time. This one is being build one wire at a time.
I also took some time to catch up on my HDX interconnect drawing.
