08 Dodge Durango A/C

The belt driven pulley on the A/C compressor turns all the time the engine is running. What you want to look for is the metal disc the size of the pulley, on the face of the pulley. This disc faces forward and that is what turns with the compressor. Don't touch, just look with a flashlight. With engine running, if these disc spins the compressor spins. I really don't think you will find the compressor (and disc) spinning with switch turned off. Forgive me if I over explained it but I had too many ideas at one time.