Engine fans not comming on. Overheating Ford Focus

I had problem with my cooling system. After I traced out, I found out that my cooling fan is not working properly. At first, I thought it didn't work at all. But after testing the relay, it is in fact, working. So I went to the Temp Sensor, thinking it has to be the problem. But the Auto Shop was unable to even locate the sensor, they really sucks. However, now I just notice it wasn't even the sensor's fault. The cooling fan will only turn on when the AC is on. And it will turn off as well. That indicates that the sensor gotta be working; if not the fan should either stay on or off the whole time/ it shouldn't cycle if it is not working. I am not really a electrical guy. Can any of you guys tell me where the problem is? I am suspecting the electrical wirings between the cooling system and the ac system are theultimate blame. Am I right? Answer: I have good news for you. The problem you describe, and in EXACTLY the way you've described it, sounds like your cooling fan blower resistor has burned out. This is NOT to be confused with your car's climate control blower resistor pertaining to the four speed settings. What is probably happening is you are not getting any LOW speed cooling fan operation, when commanded by the PCM. There are two cooling fans, as others have already posted. Each cooling fan has a two wire pigtail connector to it. Look BETWEEN the two cooling fans for a two wire connector exactly identical to the ones plugged into the cooling fan motors. This will be plugged into the resistor. To disconnect it, simply DEPRESS the metal clip, and pull to remove. Look for a burned out connector, as well as the resistor it plugs into. To repair this problem, you need to go to your local Ford dealer parts department to purchase the blower resistor and pigtail connector. Both of these parts are very inexpensive, even from the dealer. It is also EXTREMELY common on your car. Please keep me informed of your findings. Hope this helps. Found this answer on Yahoo answers and was Dead On !!! Melted plug and all. Ordered parts from ford and all is well.