Information

Electrical/Charging Systems - Alternators

About the Alternator

Believe it or not but your car's alternator is an alternating current (AC) generator thus the name of "alternator".  Special rectifier diodes inside the alternator convert the AC current to direct current (DC) needed for the car's electrical systems.  DC generators or dynamos have not been used in cars since around the 1960s, this is mostly because a car's electrical system needs a lot of current to power everything and the physics of alternators create the much needed current much more efficiently than a dynamo.

Most alternators are found in the front of the engine and are driven by the engines crankshaft via a serpentine belt.  The belt then spins a rotor shaft which then creates the electrical current for your vehicle and keeps the battery charged.  Like all other mechanical things, the alternator will die in time, typically because the bearings that keep the rotor spinning wear out due to dust and heat breakdown.  If you are hearing loud grinding noises coming from the alternator, it's a matter of time before the alternator will seize to work.

Most cars today have a light that turns on when you turn the ignition switch; this light is usually symbolized by a battery icon.  Chances are that if that light is not turning on or the voltmeter on the dashboard is reading low when you turn the key and the rest of the accessories in your car are working fine, your alternator may not be working.  The car may start, but as you learned earlier, it's a matter of time that the battery will drain and your car will seize to operate.

A quick way to check the charging system is to start the car and turn on the headlights. If the headlights are dim, it indicates the lights are running off the battery and that little or no juice is being produced by the alternator. If the lights get brighter as you rev the engine, it means the alternator is producing some current, but may not be producing enough at idle to keep the battery properly charged. If the lights have normal brightness and don't change intensity as the engine is revved, your charging system is functioning normally.

At the Color Works, our master ASE certified mechanic has the knowledge and tools to fix your car's electrical nightmares.  Whether it be a simple fix such as replacing a battery or an alternator, or a much more complex issue with your car's electrical system, we got you covered!