How Your Car’s Alternator Works
The alternator helps the battery to generate enough electricity to power many components of a modern vehicle, including the headlights, radio, instrument panel and more. It does this with the help of electromagnetism that is created through the rotor and stator — two key parts of the alternator which we’ll discuss later in this article. From there, the electricity is fed into the battery. In this article, we’ll look at the mechanics of the alternator, as well as some of the most common alternator problems.
What does an alternator look like?
Alternators are actually pretty small — about the size of a rockmelon. Most alternators are made with an aluminium housing, as the aluminium doesn’t magnetise, which is key to helping control the large amount of heat produced.
Inside the housing, you’ll find the stator clamped between the front and rear of the housing. As its name alludes to, it is the stationary part of the alternator. Inside the stator fits the rotor, which — again as the name alludes to — rotates around inside the stator, generating magnetic power.
Rocking with AC/DC
The type of electricity generated is called alternating current, or AC. The AC current is fed through the stator leads and then into a set of connecting diodes. These diodes work to block and direct the current as necessary; they are like a one-way valve that only lets the current pass in a single direction — turning it into direct current, or DC. Since a battery needs DC current to operate, the diodes play a very important role.
Once the alternator has generated AC and converted it into DC, the voltage that is produced can be used by the battery. However, too much voltage can damage the battery. On the other hand, too little voltage can be dangerous as well. For this reason, all alternators have a voltage regulator, which decides exactly how much voltage the battery requires.
Common alternator problems
If the alternator stops working, your battery will soon die. For this reason, your mechanic will tell you he often sees problems with the alternator being the reason that his customers’ vehicles have stopped running. One of the most common problems is the failure of the bearings that allow the rotor to spin. Usually, this manifests itself with the rotor seizing, making an ugly grinding noise.
Alternatively, you might notice your red battery light appear on your instrument panel. If this happens, it could well be that your alternator isn’t functioning correctly. The brushes of the voltage regulator may be worn out; the diode bridge could be faulty; the stator could be damaged; or corrosion, dirt, or loose screws could be wreaking havoc.
Thirdly, there could be a problem with your serpentine belt — that’s the long belt that guides many of the parts in your vehicle, including the alternator. If the serpentine belt is worn out or simply loose, then your alternator probably won’t work properly. Luckily, a faulty belt is simple to replace, so be sure to check that the problem can’t be solved as easily as this before you fork out for a brand new alternator!
Please give us a call should you need an alternator replacement at your home or workplace at a time that suits you.
