I have a 2004 Z71 Tahoe 4x4 with rear AC and 225K miles. It has all original AC equipment so this is its first failure. No codes, no cold air. HP Tuners shows “AC Pressure (Disable)” and I am able to override that and get the compressor turning and cold air as shown in the video so the compressor clutch circuit is fine. You can watch the voltage pressure rise when the compressor engages in the video. I replaced two pressure sensors, one on the Receiver Drier (two wires) and one on the discharge line (three lines) and still no spinning compressor. The All Data shows a third pressure switch on the back of the compressor but there isn’t one on my truck and no wiring harness for one so I don’t think All Data is correct. Since HP Tuners is showing “AC Requested”, I figure my HVAC control box inside the truck is working. Any ideas? Is there a safety pressure switch internal to the compressor and wired to the AC compressor harness? Which pins on the ECU should I test out for broken pressure sensor harness wires? Thanks!