Air won't cool when the car is stopped on a 2004 chevy cavalier. car temp is normal

Make sure electric coolant fan is running.if not check or replace fan relay.the coolant fan has to be running to cool down refrigerant in condensor.so refrigerant in condensor is cooled back down to high pressure liquid so it can go to evaporator.see ifcoolant fan not working.the AC is not going to cool.when you driving the condensor is cooling down from moving air when car is going.when you come to a stop.cooling fan suppose to be on so condensor gased can be cooled down.