I have a 2005 CTS that started to overheat slightly today. I was driving home in 115 degree weather in Phoenix. When I got home I raised the hood and one of the electric fans was running, but the other was not. Is there ever a situation where one fan should run and the other does not? Is there any reason why one fan would not be running with the car slightly over correct temperature? Are there two separate electrical connections for the two fans, or only one? Any help is appreciated. Thanks.