The A/c system is only blowing cold air when the RPM of the vehicle is up. When stopped, if the car is put in neutral and RPM increased to about 1.5-2000 the a/c will begin to blow cold. It also blows cold while the vehicle is moving.
Butting sitting at a traffic light in neutral without RPM it will blow uncooled warm air (south florida). We checked the 134a and it was in the red on the gauge. The condenser fan seems to be spinning at all times. I cannot get a could view of the compressor but it seems to be always spinning regardless if the A/C system is on or off.