Have a 2000 Silhouette the cooling fans wont come on unless the ac is on?

If the cooling fans in your 2000 Oldsmobile Silhouette only engage when the AC is on, it could indicate a problem with the engine's temperature sensor, the fan relay, or a wiring issue. Typically, the cooling fans should activate based on engine temperature, not solely on the AC. You may want to check the coolant temperature sensor and the fan relay for proper functionality. If you're unsure, it might be best to consult a mechanic for a thorough diagnosis.