Why Do You Need a Car Alternator?

Your car alternator helps to power your car and gets it’s name from the term alternating current (AC).  The alternator takes the mechanical energy, generates electricity, and sends it to your car motor recharging the battery.  The current in-turn powers the electrical components of your car like the exterior lights, interior lights, and instrument panel.  

WHERE IS THE CAR ALTERNATOR LOCATED?

The car alternator is most often found near the front of the engine and is bolted with brackets at a specific point.  One of the brackets is usually fixed and the other bracket is adjustable which allows for drive belt tightening.  The crankshaft drives the alternator and most new vehicles have one belt for both alternator and the crankshaft pulley.  

WHAT ARE THE COMPONENTS OF A CAR ALTERNATOR?

Most car alternators are relatively lightweight and small.  Car alternators are lighter in weight because alternator housings are constructed of aluminum, which does not magnetize.  Not only does aluminum help keep the weight of the alternator down, it also helps to dispel the heat caused from generating the electrical current.  Keeping the heat low is essential to the alternator’s operating efficiency.  Older alternators will actually have external fan blades on the rotor shaft behind the pulley.  Newer alternator models have cooling fans inside the alternator housing.  The rotor shaft is located at one end of the alternator and at the other end are the slip rings.  The alternator also has vents on both the front side and the backside, which helps to dissipate heat.  Also on the back of the alternator are several terminals, which are connecting points in the electrical current.  These terminals do various things including sensing battery voltage, closing the circuit to the warning lamp, bypassing the regulator, turning the voltage regulator on, and connecting to the battery.  The rotor and the stator are two components of the alternator that actually produce the power.  

HOW DO I KNOW WHEN MY CAR ALTERNATOR IS GOING BAD?

Like many components of your car, your car alternator has moving parts, which tend to get dirty.  Your car alternator can also start to fail as a result of stress from extreme heat or cold.  Sometimes you know when the alternator is failing because the radio begins to cut out, the dash lights start to dim, the heater quits, the headlights stop shining brightly, and the engine may die.  One of the most common sources of an alternator going bad is bearing failure.  Alternator bearing failure is often characterized by a loud grinding noise.  Once you start hearing this noise, it’s only a matter of time before your alternator fails.  Most car dashboards will show an indicator light when your car alternator is having problems.  Another way to see if your car alternator is failing is to have one of our technicians use a voltmeter to check the voltage.  If the voltage falls below 12 volts, it may indicate a problem with your car alternator.  We will also check to see if things like the air conditioner, radio, and headlights are drawing electrical power.  Another component that we will check is the serpentine belt to see if it is worn or loose.  If this belt needs to be replaced, it can cause the alternator not to work properly.