Well, I dug and dug through the service information but I just could NOT find a published spec from Chrysler on the fan turn-on temps. I did find that all Hemi's came with a 195 degree thermostat, and the ones I've driven seems to hover in the 210-215 range.
There are, apparently, two different cooling fans used depending on whether you have the "Max Cooling" package. The standard fan is 350 watts, controlled by a simple set of relay's that control either high or low speed. The Max Cool package has an 850 watt fan that is PWM controlled directly by the PCM, giving it both higher cooling capacity but a much broader range of speeds to work with.
I would have to imagine that when you say your truck has HD cooling that it includes the bigger fan. All I could find was that the PCM has an internal logic that uses engine coolant temp, oil temp, trans fluid temp, ambient temp, and A/C pressures to decide when and at what speed to run the fan.
Last edited by 14Accent; 04/28/20 05:24 PM.