How do AC Compressors Work?
Like the rest of your engine's accessories, your A/C compressor attaches to the front of your engine with a bracket. A belt then drives the compressor's pulley. When you switch your A/C on, the A/C compressor clutch activates the compressor. The compressor pulley free spins when you're not using your A/C. Therefore, you’re likely to experience better gas mileage when you’re not using the A/C to cool your vehicle. If either the compressor or the clutch fails, you may hear squealing or grinding noises coming from under the hood of the vehicle whenever you attempt to use the A/C.