Hi guys I'm hooking up a Spal fan controller that can use the stock temp sensor for the coolant reading by the OEM cpu. Can anyone tell me where this sensor is located? Is this a sensor in the head or is it on the plumbing or block? Truck is a 05 5.4 fx4.

The Spal guy also said to be careful with this sensor because the fords have an atypical way of measuring the voltage.

His comments were

I'm not sure your truck will have the problem sensor mentioned in the manual. The problem with some of the newer Ford vehicles is the sensor is a multi stage sensor, which mean the sensor resets at a certain temperature and increases in voltage then starts dropping again. To use this type of sensor the controller will need to be programmed over that temperature threshold and will also come on at much lower temperatures, then stop and start again at the higher temperatures.

You can test the sensor once you locate it and measure the voltage on the sensor as the truck warms up from a cold start. A normal sensor will just drop in voltage as the temperature increases. The multi stage sensor will drop in voltage until it reaches it set point ~200 degrees and then reset increase in voltage and do the drop again. The controller memorizes the voltage settings so if the vehicle is running through them twice the controller will also run through its programming twice. You also have to program above the set point or the low setting will higher than the high setting resulting in the controller not working. It you have this sensor you might want to use a sensor just for the controller.

 

This is incorrect, on several levels. That's not an engine coolant temperature sensor (ECT); it's a cylinder head temp sensor (CHT), which is different. And that step in voltage doesn't occur within the sensor; it occurs within the PCM. Read this caption:

 

I had a feeling this was the response I would get back... guess I'll figure something out.