Audio Systems: power turns off, something weird, low water

Question
I have a 1997 cavalier which seems to be doing something weird. When i play my stereo and have the air conditioning going when i stop at a light or stop completely the stereo will go off then come back on. However, when i am driving i can have both on at the same time with no problems.. What is happening?

Thanks!

Answer
sounds like a current problem, have your battery and alternator checked, to prove it, get it to mess up, put car in neutral and rev up motor. if works, it means you dont have enough current available at a low rpm, meaning either low water in battery, bad battery and/or alternator.