Most people will never think twice about the condition of their A/C compressor until it stops working. The A/C compressor is the heart of the air conditioning system, without it you have no A/C. Though the compressor can fail for a multitude of reasons, most commonly the two parts that will fail are the compressor motor its self or the clutch that engages the compressor to run will fail. Some compressors will let you change the clutch without replacing the whole compressor, others you have no choice but to replace the entire unit. If you are looking for a replacement, you can depend on Hancock A/C compressors.