You know when pulling a trailer or going fast a long way that big fan come on. Its really loud and you cannot miss it. It that the big fan that comes on when the truck is crancked and runnign or is it a diffent fan? what makes it louder? how does all that work? thanks. been wondering abuot it for a while

 

its your clutch fan kicking on, its the same fan just spinning alot faster. youll see the silver(usually) finned item on the front of the fan. as the water temps increase the coil on the clutch tightens allowing it to spin faster to cool the motor.

jiMMy

 

Yes I hear alot of guys complaining about it on 03 and up trucks but I think they just complain more because those trucks don't rattle so it seems really loud

 

^^^Real trucks rattle! WHOO! But hey, whats wrong with a little noise, lol

 

Jimmy pretty much nailed it. Inside that finned hub is silicone oil, what that does is allow the fan to rotate slower than the pulley when the engine is at normal temp. This saves fuel and is quieter than having the fan rotate at the same speed as the pulley. When the little coil thing on the front of the fan clutch heats up, thet the clutch engages and locks the fan to the pulley. Things get noisy and cool down fast.

 

is there a way to hook this up to a toggle switch so i coudl make it turn on whenever i wanted or is it just better to leave it alone?

 

No, the system is mechanical. Horton makes (or at least used to) an electric fan clutch for these trucks, but it is/was pricey.

 

Well i think it sounds pretty cool when it kicks on. I moticed it also kicks on in the morning when i first go. well thanks for the help yall