Chevrolet: air conditioning, coolant leaks, serpentine belt

Question
Hi Keith! My mom has a 94'Cavalier. Just today when she puts on the air,(it has been very hot in Chicago)at the same instant the engine compression drops down and if you continue driving, the car will stall out.If I feel that the engine is ready to stall, I shut off the air and lo and behold, she runs like a champ. Yes, we had it serviced for the season and it was recharged with the new freon.There is no coolant leaks(that I see on the ground or engine compartment) and the serpentine belt is new and tight. Thank you for your proffessional observations and input!   Ronny

Answer
Hi Ronny, take your moms car back to the shop and have them check the compressor, it sounds like its starting to sieze, maybe they forgot to put the peg oil in with the refridgerant. In the meantime, tell your mom not to turn on the air condition until you find the problem because the belt could break and cause the engine to overheat and cause serious damage. If you need more info, just let me know. Regards. Keith.