Cooling fan cuts in when not required

So, OTR your fan is fine, but during initial startup or idling stationary it'll cycle on and off over the course of 5-10ish minutes.

 

I haven't noticed it coming on going down the road. If it's cold and I idle the truck the fan will intermittently come on. Also when it's below freezing and the truck has been idling, when I start to roll out it will come on.

 

Mine do thé same

 

Since GHG14 model Detroit engines do this by design to calculate the true ambient air temperature to figure out if the DEF heaters need to be activated.

 

I’m having the same exact issue did you ever find a solution

 

I saw someone mentioned a binary switch. My trinary switch on my '16 went out several months ago which causes the fan to not shut off. Possibly it is on its way out.