Had a 2005 3500 come into my shop with some different a/c issues. First issue was it was stuck in defrost mode. Found the vacuum failure at the tank and replaced it. Now the compressor will not turn on when it's turned on. Tested relays and fuses, even replaced climate control. I can use my scan tool to turn on the compressor so I thought the Pressure switch or clutch switch was bad. I replaced them but still no response except when I use my scan tool. Freon levels are fine as well. Anyone else had this issue? (also, I have replaced the mode actuators)