I have an 87 4.0 liter with the stock clutch fan and electric secondary fan for the cooling system.
My question is in the winter when I first start up the cherokee in the morning with a temp in the thirties the clutch fan is spinning all the time. Is this normal for a clutch fan?
I thought that the clutch should be temp sensitive and when it is cold not engage and spin the fan. And only spin when it reaches a set temp.
Does any one know how these clutch fans are to operate on the 4.0 liter?

 

I have a '99, but I also thought I had an over-active cooling fan. Turns out the thing will run like crazy when the defrost is on. See if it makes a difference with the defrost on or off.

 

It will still spin, because of friction and inertia, when cold, just not a "lock up" condition as when it is warm.

usually when a clutch goes out, it will not "lock up" not the other way around

 

My theory on this was that when you turn it off, the temp rises and the clutch engages. So the next time you start it, it is locked up for a few seconds. This is entirely based on theory and I have never seen the inside of a fan clutch.

 

A clutch fan will always spin, the clutch just determines how fast.

 

the clutch fan will alway spin when the engine heats up the internal clutch will cause drag to occur on the blades thus creating more air pull thru the radiator