I'm starting to diagnose this. I'm not stupendous at AC work though. But this is a hobby car so I will learn and have gauges. Issue: Blows ICEY cold air when I start car for first time that day. After a few minutes AC system stops working and blows ambient air. It may randomly blow cold air again but then goes back to blowing ambient air. Diagnosis: Both high and low sides are HOT to touch. Condenser is warm but not hot. Static pressures are at 90 PSI for high and low side (car parked and not started for a week when tested). Blender door forced to full cold and unplugged to ensure stays on cold (had had issues with it in past). Electrical connection to compressor clutch is good from fuse box. Thoughts? My main concern is making sure the control system is working before I start hooking up gauges, vacuuming system, etc. My faults in past with AC work was starting with the Refrigeration when the issue was the control system. However, I don't have info on the control system for this car. Additionally, problem started after I installed a new transmission cooler line. AC worked perfectly prior to that. I noticed wiring harnesses near bottom of engine were in horrible shape. I tried shaking various lines to see if clutch would engage and tested the clutch line. All seemed good though.