Fan

[Chamberpains]

Stop throwing parts at it. Your getting excited and doing dumb things. Calm down and think it thru. 1st step is to have Insite command the fan be on in diagnostics. Then go to monitor switches and make sure it infact says the ecm is commanding the fan on. If its not then its an ecm problem. Then go to the fan and check the airline physically remove it and make sure it doesn't have air going to it. If it has air going to it then there is a plumbing issue. Your solenoid switch is stuck or being commanded open. Figure out whats causing it. If no air is going to the fan and it just spins freely than more than likely the clutch in the fan is shot. Most hub manufacturers sell the clutch rebuild kits. Go get 1 and replace the worn out clutch. They more often than not can be replaced with the hub on the truck. But I've never worked on a Prostar so 1 of those guys will have chime in. But only after you narrow down what you've check and confirmed and then let us know what all you've check and confirmed. We have semi good vision but still can't see the truck from here.