How to tell if Jeep fan clutch is bad?

Here's a way You can see if Your Jeep's fan clutch is failing or already failed. Drive Your Jeep, or idle it, until it's at operating temperature, around 210 degrees Fahrenheit. Then, turn off the Jeep. I repeat, turn. Off. Your. Jeep. I want to emphasize that, there, for You. Shut off the engine, and pop the hood. Now, depending on how skittish You are, You can use Your hand, or a small, sturdy rubber handle (such as You'd find on kitchen utensils) or in a pinch a hammer handle, and try to spin the fan. If You find there's little or no resistance at all, it's quite likely the fan clutch is bad. If the part's bad, You can pick up the Duralast brand Fan Clutch 922615 from Autozone for around $40; replacing is pretty straight-forward and something You'll likely be able to do --- again, though, with the engine off!