Engine Cooling Fan - Cummins

[CENTEX Ram]

I've got a 2012 Laramie Longhorn long bed with a Cumms. The fan sounds as though it's engaged all the time-even on cool morning starts.
Any idea where to start troubleshooting?

 

[truck2014]

I've got a 2012 Laramie Longhorn long bed with a Cumms. The fan sounds as though it's engaged all the time-even on cool morning starts.
Any idea where to start troubleshooting?

Does it quiet down after the truck warms up ? If so it's possible you have an exhaust leak .

 

[06 Dodge]

I've got a 2012 Laramie Longhorn long bed with a Cumms. The fan sounds as though it's engaged all the time-even on cool morning starts.
Any idea where to start troubleshooting?

If the fan noise stops a short time after start then its normal, my 2022 does this often...

 

[nlambert182]

It is engaged right at startup, but should spin down soon after. That's normal. If it's constantly engaged no matter what the fan clutch is the likely culprit. I've had to replace a couple. They fail engaged.

If it's acting normal until you turn on the AC and then it stays fully engaged the whole time the AC is running regardless of outside temps you may have a bad AC compressor. I just replaced mine and that's what it was doing.