Vari displacement compressor, blowing warm air

[Little]

Hello everyone. New to the board. I have a 2016 Kia Sorento v6 with a variable displacement ac compressor.

Last year my wife who is the only driver pretty much of the vehicle said the AC would get very warm at idle and would only start to cool when driving again. This year the AC will not blow any cold air. I bought a can of refrigerant to check the pressure and pressure at 40psi in the green. I don't have ac guages to check both the high and the low sides. After reading about these style compressors, the symptoms are pointing towards the control solenoid in the compressor. Here is the hiccup... I checked the voltage at the plug that goes directly into the control valve and it is only reading 9 volts whether the AC button is on or off in the car. Now I know that these style of compressors will vary the voltage depending on how much cooling demand the interior temps are requiring. Any ideas what could cause this?