Malaysia Car Market News and Guides

Car Alternator & Its Signs of Failure

19 Oct 2015

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Some time ago, my Vios started acting up on the way back to Penang from Cameron Highlands. Lady luck was with me that day, and my car rolled itself into a workshop without needing the services of a towtruck. It was quite a stroke of luck, as the car promptly refused to start once it arrived at the workshop. As it was pretty late by the time I got to Sungai Dua, Bayan Lepas, I left my car with AV Advance Tyre & Car Care Sdn Bhd and came back the next morning. Along the drive back to Penang, I noticed some quirks with regard to my car’s performance which was explained by the mechanic later. As it turns out, the quirks that I noticed were signs of a failing alternator.

Now, what exactly is an alternator?My Defunct Alternator

Within a car’s electrical system, an alternator is used in modern automobiles to charge the battery and to power the electrical system whilst the engine is running. A battery is used to start the car, but the alternator is what keeps it running. Basically, it controls the flow of electricity within the system, and a failing alternator would leave you with half-fired spark plugs, dimmed lights all around, and reduced performance on most electrical components.

Reconditioned Alternator

To give you guys an idea the costs involved in replacing an alternator, I drove a Vios and had two options at this juncture.

  • Option one is Toyota OEM (Original Equipment Manufacturer) sourced alternator which would set me back around RM1800+.
  • Option two would be a compatible, reconditioned alternator sourced by the shop, which would cost me RM580.
    I went for option two; OEM is nice and all, but in my opinion, it is not worth three reconditioned units.

Battery Warning!

Sign one is a no-brainer, and it is the warning light on your dashboard, which normally comes in the shape of a battery, or the words “ALT”/”GEN” abbreviated for alternator or generator. Contrary to common sense, the battery icon on your dashboard does not always indicate a battery problem. On most cars, the dashboard battery icon is connected to the alternator’s voltage output, which lights up when the alternator’s output is below a certain threshold. Electricity is a finicky thing, and a failing alternator is almost always preceded by a battery light which flickers, indicating unstable/lowered power output.

Dimmer Headlights!

Sign two, dimmed lights. All things electric in the car would be operating noticeably weaker due to unstable flow of current. All lights operating on the vehicle could be affected, ranging from headlights to the dashboard display. Powered windows and powered seats might experience a total cut-off of electricity as modern vehicles are pre-programmed to prioritize the essential functions allowing control of the car. The In-Car-Entertainment (ICE) system would normally be the first to lose power should there be a lack thereof.

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Sign three, a heavier steering wheel. Nowadays, most cars rolling off production lines are equipped with Electronic Power Steering (EPS); as it is an electronic component, a failing alternator would provide it with less electricity, causing your turns to feel more sluggish and heavy. Only cars that use EPS would feel sluggish-er steering with a failing alternator; cars that use hydraulic steering such as Preve, Saga, Savvy and Gen2, would not be affected.

New & Old Serpentine Belt

Sign four, smell of burning rubber, or burning anything for that matter. The engine pulls the belts, and the belt pulls other pulleys. If the mechanism is in anyway misaligned/damaged, it will cause excessive friction and lead to the smell of burning rubber. If you get a strange odors that you won’t quite label as rubber, understand that it could be the smell of “hot wires”. As alternators fail, the energy that goes through the wires become unstable and in certain circumstances, the energy becomes so high that the wiring is overheated and emit a strange smell, which is polyvinyl chloride (PVC).

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Sign five is, a dead battery. You might see a dead battery in your car and tell yourself, “It’s been a year since I changed it, guess it was time for it to go.” But the average car battery is supposed to last 2-4 years, why do I change mine every so often? Well, the problem could very well lie with your alternator. As cars age, alternators often get neglected and fall into disrepair. But, they still do what they’re fundamentally designed to do, and that is disperse electricity throughout the car. As long as that function remains intact, an average car user might not notice this defect and chalk up whatever problems to the car’s age. A failing alternator would cause the battery to work harder than normal, resulting in a shorter lifespan for the battery. In short, batteries that need to be changed too often could be a symptom of a failing alternator in itself.

Sign six, rough engine sounds when idling. Before alternators finally give out, they give off a noise which has been described as “growling” or “whining”, most noticeable when just starting the vehicle. The engine generates a high amount of energy when it is revving high; conversely, it generates lower energy when idling, and this is when the alternator needs to work doubly hard to generate the requisite electricity to power all electrical components of the car, resulting in the growling noise.

14 Volts, healthy alternator.

Alternators require replacement eventually, and you can maximize your alternator’s life by taking proper care of yours right now. If you need to jumpstart your car, do it the proper way or risk damaging the alternator, and do not overload the car with power-consuming accessories/gadgets. Apart from that, it is also important to look at the alternator regularly to see that there are no liquids leaking and that the belt is aligned and in good condition.

Take good care of your car, and it will take care of you.

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This guide is written by Kelvin1987. Send message to this author for further discussion on this article.
In his youth, Kelvin Ang loved cars and enjoyed fixing cars with his father. Today, Kelvin is a car enthusiast sharing his passion with the world! Follow his blog on for more tips on cars!