@JohnClassic Point of clarification: The extruder fan should be on whenever the printer is powered on. That is the fan on the front of the hotend housing, blowing on the hotend heatsink. Cooling the top of the hotend stops filament from melting too early. The part cooling fan is the only fan that can be controlled. That is the blower fan on the right side of the hotend, with the little duct hanging below it. It is meant to cool the melted filament that was just extruded out of the nozzle. It is at least not intended to cool the nozzle itself or the hotend. It would be counterproductive if it did. Normally it is turned off, and turned on some time into the start of a print (like 5 layers}, depending on your settings. If that's not the case, and you didn't intentionally modify it, then something went wrong. (edit: I was mixing "extruder" and " hotend")