The short of it, I am experiencing a loss of cool air in my truck after about 15mins of driving. I picked up a pressure gauge to put on the low pressure side of the coolant line and it went something like this:
1) idle for 1min: Pressure at the low side of the 'good' section
2) idle for 5mins: Pressure at the high side of the 'good' section
3) after 10min driving, A/C temp no longer cold: Pressure in the 'Warning' section
4) after 10min driving, A/C turned OFF: Pressure still in the 'warning' section
Also, I can't hear the A/C clutch turning on/off when I turn the A/C on and off in the cab. Appears that it's likely that the clutch isn't disengaging when the pressure reaches the proper level.
A) Bad Clutch
B) Bad sensor which is supposed to control the clutch.
C) orifice valve clogged causing increasingly high pressure.