Tried this, worked first go for me. Seems to be a fair bit info available although I can't quite work out some of them. Found Oil Pressure, Voltage, Water Temp, Revs, Fuel level (basically the same stuff as the instruments) but some of the others I'm not sure of.
Does anyone have a proper Falcon workshop manual, not a Gregorys or Haynes, but the proper Ford ones. They would most likely have the some info about this "hidden" feature