When it's time for a new 2012 Mazda CX9 alternator, come to AutoZone. Alternators turn mechanical energy from the engine's crankshaft into electricity through induction as the wires inside of the alternator cut through a magnetic field to induce electrical current. All of our 2012 CX9 alternators feature an output between 13.5 and 14.8 volts to power your accessories and keep your battery charged.¿Buy online for free shipping with next day delivery or pick it up at one of our auto parts stores near you.