Pontiac Repair: AC/Fan question, grand prix gt, engine fans

Question
i have a 97 grand prix gt with a 3.8 liter motor. whenever i stopped for a short period of time the car would begin to get hot. but when i began to drive it would cool down. well my AC was not getting cold at all because my compressor was not comming on, and my engine fans were not turning on. after i put a can of 134a refridgerant in my AC system, my AC was cold an my fans worked fine. well as the next few days went on my AC got warmer and warmer and then my fans stopped working the car heated up once again.i repeated this process and it keeps happening. so i was wondering if the AC and the engine fans are connected somehow, or if a switch or sensor is bad.

Answer
Hey Mat:

Yes they are tierd in together. they use the same fans. When the A/c is working there is a pressure sensor in the hi side line and when that pressure get high enough it tells the engine computer to turn on the fans. You obviously have a leak in the a/c system. the first place to look is at the condenser. No as for why it' overheating when the a/c is not on??? It could be low on coolant. The engine computer could have a logic issue when when the engine hits a high temp it will not turn the fans on. With out the use of a engine computer can tool your gonna be out of luck. With one of those you can see the engine temp and the computers abaility to turn on the fans when the engine gets hot enough. Good luck :)