Why won't my fan clutch clutch disengage?

Silly question but sometimes its overlooked. Check that the hub is not mechanically locked with the bolts. If its a horton there is two bolt holes in the front that you can thread 2 3/8 bolts into to mechanically lock hub incase of clutch failure. Also with engine off and key off hub should be locked when key is turned on usually hub will be unlocked is it? Also inspect hub to make sure brgs are not failing and causing it to lock up.

 

Well thats good that is telling me its not the fan clutch at fault. The problem will be the control side eg solenoid, a/c demand switch etc.

 

have you checked for a blown fuse in the underhood fusebox ...15 amp fuse....number 41 possibly

 

with the engine off the clutch fan should be engaged, I/E spring engaged, solenoid has no power air has to be applied to separate clutch and free wheel.

 

He most likely has a Horton fan clutch and they engage with air and free spin with no air. I believe it is a Kysor fan that takes air to release it.
You don't possibly have a manual switch on the dash that is on.

 

what you need to do is get to an air compressor and shoot air into the fan hub directly and see if that releases it . If not then your air sel in the fan hub is bad. Then you have two options , buy a super kit and rebuild it which it comes with directions but does require a mechanically abled person or just buy a reman fan hub and replace it