If your A/C blows cold when you first fire the Jeep up, but after a few minutes blows warm air, your clutch might be shot. If you shut the A/C off for 30 minutes and it then blows cold again, time for a new clutch. Just like the clutch between the engine and manual transmission, this clutch can wear, too. Depending on use, it should last 100,000 miles. However, most clutches die due to too little oil in the system. The resulting heat from the metal-on-metal contact in the compressor overheats the sealed bearing the clutch pulley rides on and fries it. Note the nut (circle) used to check backlash of the compressor.