I have a 1996 GS300. At times my AC is working fine, blows cold air. Now and then the AC light will flash and the system blows warm air. After turning the AC off and on several times it begins to work, sometimes for a long while and other times just for a short while. I took it to a mechanic and was told the system is fine and it could be the controller. I replaced the climate control and I'm still having the same problems. I'm about to order an AC amplifier since it's not too expensive. Anyone have any thoughts?