Check status menu to see if the unit is calling the compressor. (On main board go Down or up until you are on “Status Menu” > Enter> Up push all the way up to “Colling Stages” > Enter > If Y1 has a number)
If Y1 is calling, go to your terminal strip and check the 24V Wire (On the terminal Strip Place you Voltmeter on “common” & “Y1” and it should read 24VAC )
Check pressures to see if the low-pressure switch is off. (Need to charge system with refrigerant)
Check to see if the outdoor fan is on, may have turned off by high pressure.