The Alternator and Your Car

Your car’s electrical charging system is generally made up of three major components: the battery, voltage regulator, and alternator. The battery and alternator work together to generate power for the electrical components of a vehicle.  Alternators are generally found near the front of the engine.  They are driven by the crankshaft which converts the up and down motion of the pistons into a circular movement.  When this movement turns the components of the alternator it produces AC power through electromagnetism.  

History of Your Alternator

An alternator gets its name from the term alternating current (AC).  Thomas Edison is known for inventing the first light bulb and many other electrical mechanisms.  It was actually Nikola Tesla that developed the first AC induction motor in the late 1800s.  While Edison was out to promote direct current or DC power, it was Tesla who proved that AC power was superior.  AC power can produce higher voltage much more efficiently and that is very helpful to run a car’s electrical system.

Alternator Components

Alternators are usually small and lightweight.  Most alternators found in passenger cars and small trucks are constructed using an aluminum outer housing since lightweight metal does not magnetize.  Aluminum also dissipates the tremendous heat generated by producing the electrical power.  If you look closely at an alternator, you will also see vents on the front and back also for relieving heat.  A pulley is attached to the rotor shaft on the front of the alternator.  When the engine is running, the crankshaft turns the drive belt, which spins the pulley to turn the rotor shaft.  The alternator transfers this mechanical energy from the engine into electrical power for the car.  

Lifespan of the Alternator and Replacement

If your alternator is not functioning, the electrical components of your vehicle will quickly drain your battery.  Since today’s automobiles cannot properly function without the electrical system, this can be a big problem.  Alternators have moving parts, get dirty, and are subject to stress from the drastic temperature changes.  All of these causes can make the internal parts gradually wear out.  The most common is bearing failure.  The needle bearings allow the rotor to spin freely to produce electricity.  When these fail, the alternator will not work efficiently and can completely seize up.  This failure will normally cause a loud grinding noise.  If you suspect this problem, quickly consult one of our mechanics to prevent a breakdown.  Older vehicles with generators tend to require much more maintenance than newer models, but there's no standard rule for how long an alternator will last.  Generally, alternators are less expensive to replace than many other parts of the car.  Some people still may search for an alternative to purchasing a new replacement alternator.  Some new alternators can be around $230 but if you are willing to use a remanufactured one, it might only cost $160.  Many times remanufactured alternators are easy to access and simple to replace.  More often today, cars are running out of room under the hood.  This has caused some manufactures to place the alternator in a less accessible spot.  If this is the case, you may want to let an experienced mechanic do the job.  They can save you a headache and get the job done much quicker than most people.