Another fan question (non-electric)

[A-man930]

So I've been wondering for a while, is the belt-driven radiator fan in my MJ supposed to be on all the time? Or is it only supposed to engage at a certian temperature. All my other cars have had dual electric fans, so I'm not familiar with clutch fans. I was under the impression that they dis-engage at times.

[chicofuentes0224]

No, I think they are always on. They just get faster as the revolutions get higher.

[HOrnbrod]

So I've been wondering for a while, is the belt-driven radiator fan in my MJ supposed to be on all the time? Or is it only supposed to engage at a certian temperature. All my other cars have had dual electric fans, so I'm not familiar with clutch fans. I was under the impression that they dis-engage at times.

 

Google MECHANICAL CLUTCH FANS. Will tell you all you want to know. :nuts:

[Oizarod115]

basically it always spins, but its not always engaged enough to matter, the mechanical clutch is metal that expands and locks it in to spin at engine speed when hot enough, then when it cools off it should freewheel (but it'll still be spinning just because its not perfect)

 

to check if its working it should be tougher to move by hand after getting it nice and hot (and shutting off the motor)

than it is when its cool and (the motor is shut off)

 

basically the same idea as an electric fan but you can't really see it operating. old cars had just belt driven fans with no clutch and they drained engine power, as well as causing it to take forever to warm up