Air Conditioner Fans Stopped Working

I am a proud owner of a 1986 Silver Spur with 110,000 miles on her. She has ran fantastically, however, I recently had to have the Radiator, Clutch, and Fan replaced due to a Fan Blade breaking off into the Radiator. This was early May, and the new parts were factory parts and worked done by certified Rolls-Royce mechanic. At the end of June, the Air-Conditioning Fans stopped working periodically on hot days. I simply hit the reset trip switch for the fans, but now, that does not work. The Air-Condition works fine, just the fans stopped working. I was wondering if this could be due to the Radiator Fan Temperature Switch? Any help in diagnosing the cause and steps to repair would be much appreciated. Thanks :)