Was this problem solved at the end? I am having the exact issue with Link G4+ plug ins on my FD.
"When AC pressure switch(in series w AC button) is open due to high pressure, voltage @ pin 4V is 0v=gnd.
This means that Vipec ECU does not understand that AC systempressure is to high and just keeps running the AC compressor. "
Once the AC pressure switch 'clicks', I no longer able to turn off AC compressor, it will stay on.
It's like the pressure switch is working the opposite way as it suppose to be.
