The alternator in your Mazda Protege keeps the battery alive by charging it while the engine is running. Without the alternator, you would need to jump your car every time you needed to drive it, which would be quite a hassle. Unfortunately, when an alternator goes bad, this is exactly what needs to be done, so keep your battery charging properly by replacing your own dead alternator.
Disconnect the negative battery cable before you begin working. This will lessen the chances of personal shock and drainage of the battery while working.
Use a large wrench or pry bar to wedge the accessory drive belt off of the alternator. This can be difficult, but with enough force the belt should pop right off.
Loosen the top bolt of the alternator, found directly above, and set it where you will find it later. New alternators rarely come with this sort of hardware.
Disconnect the power to the alternator. The electrical connection is underneath the alternator and can usually be removed with a 12-millimeter wrench. You may need to lay underneath the car to reach it.
Remove the bottom bolt from the alternator from underneath the vehicle. Set it aside. When this bolt is removed the alternator should come out easily from above the car.
Put your new alternator in place from on top of the vehicle. From underneath the car, install and tighten the bottom bolt of the alternator. Tighten the electrical connection to the alternator with its mounting bolt.
Place the accessory drive belt over the alternator's drive shaft.
Put the top bolt of the alternator in place and turn the adjuster until the accessory drive belt is nice and tight. Tighten the bolt with some force. You don't want the belt to come off while driving.
Reattach the negative cable to the battery terminal.
