So what I have concluded is the 4 pin square connector is a junction, one side feeds +12v to the HVAC switch in the car & returns in one of the other 3 wires (only 3 of the 4 used) to energize the compressor, which is the bottom left connector. And the round connector is a pressure switch in the power steering line, if at full lock & high pressure, the AC kicks off as to not bog down the engine & possibly stall it.

Wow, This is a good thread and a lot of good info.