Good day, I was experiencing the same overheating issue with my 01 Trooper and I was ready to replace my fan clutch as well but thought to flush my system first. I remembered adding diluted antifreeze in the past and noticed my fluid levels were low. I simply added straight antifreeze to my coolant system and my trooper has not overheated since then. This may just be my fix but I thought that this may also work for someone else. Cheers!Clutch arrived. Installed it. Drove 30mi on the highway. Overheated.
Looks like I got too cocky about the fan.
When I stopped (with the car overheated) I checked the fan and it had a little resistance when I pushed it with my hand. It stops when I stop pushing; no freewheeling. I'm not sure how locked up the clutch is SUPPOSED to be but the amount of resistance I experienced did not seem enough to get the fan really spinning fast. This is with the new clutch.
All that's left is the pump and radiator. Time to google.