The external system is not connected check the connection

[Quadragin]

2005 GX470 with NAV when I try and turn on the AC or Heater, I get the following error message on the NAV screen "the external system is not connected check the connection of the air conditioner" the HVAC controls are also dark.

So, I bought a used non-NAV controller of the appropriate model number for my year, unplugged from the HVAC computer (yellow box) at the passenger kick plate plugged into the Non-Nav. The non-Nav HVAC controller also does nothing.

Any Ideas where to start. I cant seem to find a diagram to see it the HAVC controls are getting power...