So you are unlucky to find out your car didn't start. After having the road service come and getting your car to the repair shop you find out that the Alternator is bad. But what does the Alternator have to do with the car starting anyway? The alternator is an imperative component to the operation of your vehicle. Think of the alternator as the automotive equivalent of that little white box that your cell plugs into……
Lets start off with what an alternator does for you. The basic function of an alternator is to take mechanical energy (from your running engine) and turn that into Alternating Current Electrical Energy (to power all of the electronics). The mechanical energy is transferred to the alternator through a drive belt. This drive belt is connected to a rotor through a pulley. The rotation of this rotor within a stator produces Alternating Current Electricity. You may remember from high School science that alternating current (AC) is what is typically used in homes and direct current (DC) is what is stored in a battery. So unfortunately for our standard battery powered cars alternating current is useless! So there is one last step in automotive alternator. The Alternating Current (AC) is converted to Direct Current (DC) through a rectifier. Now that we have the proper DC voltage being produced we can use this to charge and maintain the vehicle battery.
So when the battery has no voltage remaining one of the first things that your mechanic will check is your alternator. Just like when you phone dies you would check to see if the charger is plugged in! The alternaotr is responsible for maintaining battery voltage as well as providing additional electrical supply for your vehicle. Without a properly charged battery your car will not be able to start and drive!
Symptoms of a Bad Alternator
A dead battery is just one of the potential symptoms of a bad alternator. You may also experience some warnings on your dashboard prior to the battery dying. Some vehicles will have a battery shaped light, others will have a message indicating a charging fault or even the illumination of the "Check Engine Lamp". These issues do not solely mean that the alternator is at fault. Your mechanic can perform a test to determine the function of your cars alternator. If the alternator is determined to be faulty it will be rebuilt and or replaced.