2017 FORD EXPLORER 3.5 COOLING FAN CYCLES ON/OFF

On vehicles with electric fans, the fan is not designed to come on until the engine reaches operating temperature, around 195 degrees. There could also be a sensor which turns on the fans anytime the pressure increases inside the AC system. You could have a defective heat sensor associated with the thermostat causing it to not come on. The Thermostat itself could be defective. If you change the thermostat, use the proper Motorcraft thermostat oly.

That might be possible! but the coolant temperatures, both on the gauge and the scanner show no issues. I would also feel that if the thermostat was not working properly I would get an insufficient code, I have no codes ever. I did have the reprogram for the carbon monoxide Issue preformed a little less than 2 years ago. I think this issue started happening not long after. Not sure if there is a connection or not.

If your scanner has the ability to read the cooling temperature, take it for a drive then read the temp, it should be above 195 degrees, which would cause the computer to turn on the fan. If not at 195, let it idle until it gets up there. If you get no temp reading at all, suspect the temperature sensor. If the temp never increases to about 195, you could have a faulty thermostat stuck open. On vehicles with two speed fans, there may be two cooling fan relays, check the low speed relay for proper operation. You can also disconnect the power to the fan and check if it is getting voltage to the fan on low speed operation (after warmup). A live data recorder makes all this easy. If you have access to one, use it.