Ac Not working

Typically the clutch not engaging is due to low freon level. Or faulty low level switch.

Agreed,,,thinking is a good thing ; )

It's most likely that they pressed a schrader valve, heard a hiss and think it has plenty of R134a. You could always jumper the Low-side switch with a Paperclip to see if the Compressor engages. You should already have a Manifold Gauge Set hooked up so you can see what the Compressor is actually doing and if the system is actually charged. Don't run it too long on the Paperclip - low Freon also means that oil isn't being distributed through the system and could cause a Compressor problem. The Air Gap between the Compressor Clutch and the Pulley should be between about 0.020" and 0.030"

Have a question I replace the dryer AC compressor in the AC will not blow cold and the compressor is not turning on ,i check the relays it doing the same thing it’s a 2002 F2 50 super duty