If the compressor doesn't engage, how do you know the system is charged?
Check the LPCS. You should have 12 V into it with the AC turned on, and 12 V leaving it if your system is indeed charged. IF you have 12V egressing, the clutch should engage.
Disconnect the clutch's connector and ohm out the ground. Look for around 5 ohms.
If you have 12V leaving the LPCS and the clutch's wiring is ok, the issue is probably at the WOT relay. I'd have to look at a schematic to see what to check there.