[Kaptain Kadian]

This is the way I understand it, I may be wrong, but this is what I have gathered from the forum here. The thermostat in the water neck let's the coolant in when the truck gets hot. The temp sensor for the fans needs to come on when the coolant is over a certain temperature to cool down the coolant in the radiator. If you put the temperature sender for the fans in the head, the fans could be coming on when the motor is over temp, but the temp of the coolant may be already cooler. The thermostat and coolant cools the motor, the fans and radiator cool the coolant. I would want the fans to come on when the coolant is over temperature to be able to cool the motor when it flows through the thermostat in the motor. I am not a mechanic and have a thimble full of knowledge on the subject, but that is the way I understand it. I think it mostly evens out once the motor heats up anyway and the fans will be running most of the time anyway.