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What you are looking at is your A/C clutch, it is normal for it to start and stop. The backwards rotation is also normal. The clutch engages to allow the compressor to spin this is what moves the refrigerant through your A/C system. When the A/C is not on the clutch disengages allowing the pulley to spin without moving the refrigerant through the system.
The backwards turn is the high and low sides equalizing. Once the clutch disengages the valve closes and the compressor vanes are pulled.
Sunday, February 10th, 2019 AT 10:29 PM