Ford Repair: 1995 ford mustang, ford mustang, engine temperature

Question
1995 ford mustang 3.8 engine -- temperature flucuates -- not thermistat --  what can cause temperature to flucuate and not hold a steady, constant temperature?  

Answer
There are a few things that can make the temperatur flucuate. But i really need to know under what driving conditions does it flucuate at and how hot is it actually getting? Some fluctuation is normal to a certain degree. Does the cooling fan kick in when temp reaches the half way point? get back to me with a little more info and i can ve you a more detailed answer.
Chris P