I have an overheating problem with my 95 4-runner. It go passed the half temperature mark all the way up to red when it has been driving for at least 20 min or so. I have checked everything thing including taking out the water pump and change the thermalstat. It will not go over the half temp mark when it is idling in parked. There are no leak that I can see. I also noticed that the electric fan does not go on when it reach over passed the half mark. But it will turn on when the air conditioning is on. Does anyone know that is normal? I think I remember it turns on when ever it get hot before but not sure. I also notice that the AC stop working whenever it reach over passed the halfway mark on the temperature guage. Any help would be appreciated! THanks.