Steveaf150

I have a 2010 F150 5.4. I just changed the water pump and thermostat with ford OEM parts. Now my radiator fans do not turn on. Truck is not overheating, and the thermostat opened up at 192 degrees. What is the factory coolant temperature setting for the radiators to turn on? Also what is a good running temp?
​​​​​​Thanks in advance for any advice.

dsg2003mach1

turning the AC or heat on should force the fans on at high speed regardless of coolant temp.

On older fords with climate control off low speed was usually around 208 and high around 228. I didn't see a number in a quick google search, everyone just talking about thermostat temps

Spiky

No, ac/heat should not force the fans to high.

digitaltrucker

I thought when/anytime the AC compressor is engaged, the fan(s) should at least be on a low speed, at least?

Spiky

Low ≠ high.

I cannot find a specific engine temp that causes the fans to switch to high, either.

ProjectSHO89

If the AC compressor is ON and the vehicle speed is under a set limit (depends on calibration), usually somewhere around 30-40 mph, the fans should run on low speed. High speed can be switched on based on CHT temp and evaporator core temp as sensed by the PCM.

If the AC is OFF, the fans are controlled (by the PCM ) based on the CHT temperature and vehicle's speed. I've not come across the actual numbers in any of the Ford documentation I have, but I'd expect that low speed should kick in between 205 and 215 F and high speed somewhere north of 220F.

I'd expect normal operating temp to be between 195F and 210F.

BTW, the dash gauge is pretty useless for evaluating cooling system performance unless it fails completely. Use a scan tool to monitor the CHT and or ECT PIDs.