The alternator in a Mazda6 operates various electrical devices in the vehicle while the engine is running. A voltage regulator keeps the voltage level constant and is usually part of the alternator assembly. You may need to replace the alternator if your headlights become dimmer while driving or your battery repeatedly runs down.
Determine which alternator your Mazda6 will need. You'll want to be sure the new alternator is compatible with your Mazda6's engine. Models made from 2002 to 2007 can have a 1.8 L, 2.0 L, 2.3 L, 3.0 L or 2.0 L diesel engine. Models after 2007 come equipped with a 1.8 L, 2.0 L, 2.5 L, 3.7 L or 2.0 L diesel engine.
Disconnect the negative battery cable with a socket wrench and remove the under cover. Remove the drive belt, alternator duct and heat insulator with a socket wrench. Remove the electrical connections for the alternator.
Take the three mounting bolts off of the alternator with a socket wrench and remove the alternator assembly.
Install the new alternator assembly and tighten the upper mounting bolt with your finger to hold the alternator. Use a torque wrench to tighten the mounting bolts to between 29 and 41 foot pounds. Tighten the lower right bolt first, then the upper bolt and finally the lower left bolt.
Attach the electrical connections for the alternator and tighten the bolt for the heat insulator to between 18 and 47 inch pounds with a torque wrench. Install the drive belt, alternator duct and under cover with a socket wrench. Connect the negative battery cable with a socket wrench.
