Ford F-150 (2004-2008) :: A/C Not Blowing Cold Air / Clutch Not Engaging

Here is my problem: A/C not blowing cold air, blower motor working fine, checked all relevant fuses for A/C and R202 relay under the hood. Everything is fine here. Next, low pressure switch, jumped, clutch does not engage. Next removed relay R202 (clutch relay) measured voltages (at female sockets) where pins 1 and 3 would go, voltage OK. Jumped where pins 3 and 5 would go (bypass to see if clutch engages) and it does. Appears that the pressure switches check out OK (low pressure and A/C cycling switch - although this one not sure). CarMD unit was used as well, and no codes generated so perhaps PCM is working OK? I'm stumped, as a loss of GND by PCM or perhaps a corroded or open wire issue??

Also, possible the A/C switch on the HVAC control could be bad, but the light comes on, (doesn't mean switch is good necessarily). The rest of that unit works fine, control ***** that is, fan speed adjusts properly, air flow looks good. It appears this is an electrical problem where the clutch is not getting juice but I don't know the source of the problem. However, I also noticed that when the clutch/compressor was running (temporarily as described above) cold air still didn't come out. This, I assume, would mean I would need to add refrigerant or re-charge the A/C AFTER I get the clutch to engage electrically. 2004 F-150 5.4L ....