The auxilliary fan may not automatically come on with the A/C. This fan is controlled primarily by temperature, and functions to draw air though the A/C condensor and engine radiator when the engine temp is high. This means that the aux fan will come on generally when the vehicle is hot and not moving, such as idle after running on a hot day, or in stop/go driving on hot days. When the car is going down the road at 65 mph, fans are not needed for condensor and radiator cooling. You can best test after a good run on a hot 80 degee day with the A/C on, let the car run at idle, the fan should come on.