Saturn Repair: 94 saturn cooling fan operation, dual overhead cam, temp gauge

Question
I have just bought a 94 sc saturn with the 1.9 dual overhead cam engine, 5 speed with ac. My ?  is with the cooling fan on the radiator. On my drive home the temp gauge got to 3/4 and was not coming down, I turned on the heater fan and the temp went to 1/4 then I turned it off. I noticed it was not running (cooling fan) when I got home and temp at 1/2. The fan will turn on when the ac is turned on, correct according to the repair manual. My main ? is, why will the fan not operate for the temperature changes in the engine? Any help would be welcomed. Also the manual says the fan will turn off at a certain speed. Could it be 1 of these sensors or switches?

Answer
Hi well the fan should run if the car is hot the temp has to 212 degrees which is over 3/4 before the fan comes on also your temp gauge may not be right what u have to do is get agarage to put a scanner on it and see what the computer is seeing 3/4 is most likly fine..