ranger_rick

(2014 STX)
First off I am a noob when it comes to the F150 or the 5.0.

After 75 mile highway run, I pulled off and heard a loud fan sound coming from under the hood. I turned off the heater/fan and listened.

All i could think was its the auxiliary radiator fan? But i was hearing it on the cab?

I turned off the truck and it stopped. In my experience most the auxiliary run even when the engine is off (runs until it reaches the appropriate coolant temp)

So, i came to place where i could investigate further. Dummy gauge reading upper range of normal operating temp and loud fan sound.

I went to the front of the truck and sure enough it was the auxiliary fan blowing like a SOB (or is that sucking?) Once it cooled down a little it shut off.

My question is are they always that loud and is it normal for it not to run when the ignition is off?

Sorry if its dumb question my last truck was a ranger 4.0 lol

Thank you in advance RR

Tothemax

There are a handful of threads on this same subject. They are loud. Make sure you check your coolant level and make sure it is full.

Al_Maryland

I solved it in my 2012 f150 by installing a 160 degree thermostat. I read all of the fixes. This was the only one that work in my particular instance. Good luck and I hope you find a solution to your problem.

ranger_rick

i am not too concerned about it. its truck not a luxury sedan. if i wanted quiet i would have bought a lexus lol

i am just thankful its a common problem.

i haven't had the truck that long. what is the temp limit for the stock thermostat?

RR

majorminor

I have a 2016 f150 / 5.0 with 36k on it. Recently my auxiliary fan started running all the time. Coolant level is fine. Ford dealer is NO HELP...surprise. have heard ac pressure switch may be the answer. Any help is appreciated. Read in a older model about fuse 27...but in this one..that is for power seat. HELP please.

Spiky

Fuse 27 has nothing to do with that, and they fixed that problem for your model year, I believe.

The fan running is because something is telling the computer that your temp is wrong. So, coolant level is first test, thermostat is 2nd. Past that, you can try getting into stuff like AC switches and various sensors.

Also, we have a separate forum for your year, you may find better help there.

majorminor

Thanks so much...will ck that forum when I am on laptop. I played with turning the ac off/on and it seemed to be a contributing factor. Gonna get with my trusted mechanic. Much thanks

INTMDATR

I did the thermostat, coolant level check AND OEM A/C switch replacement...STILL doing it!