my 09 6.7 runs warmer running at highway speed 75 or so. gets up to 215 engine 180 trans. then it will run 198 eng and 165 trans the next day towing a boat. same temp outside hot as heck. then the next 10 times it runs warm again. i have replaced the cap the thermostat, fan clutch as well. i know the ecm tells the fan to come on but is there a way that i can check to see the clutch come on to see if the ecm is telling it to?