What Causes an Alternator to Go Bad?

As more and more of our vehicles rely on electronics and computer-based systems rather than mechanical ones, the demand placed on our vehicle’s alternators and batteries will continue to increase. 

Alternators play a critical role in the operation of our vehicles, from the computers that manage the engine to the spark plugs that ignite the fuel, few parts of modern cars don’t depend on a steady supply of electricity. 

What is an Alternator?

When thinking of how vehicles power themselves, most people think of the battery. While car batteries are critical for providing the initial power for ignition, that’s about where their responsibilities stop. 

Alternators are what allow the vehicle to continue powering its electronics without draining the battery. Driven by the engine’s accessory belt, they take the rotational energy and convert it into electricity to be used by various systems within the vehicle. 

Alternators work similarly to the generators used in the power grid, just on a much smaller scale. A set of magnets within a coil are spun by the engine’s belt, which induces electricity into that coil. 

Components of an alternator expanded

Symptoms of a Bad Alternator

When faced with a bad alternator, your vehicle may exhibit some weird symptoms such as the following:

  • Dim or flickering lights
  • Vehicle stalls
  • Illuminated battery warning light
  • Issues with interior electronics
  • Whining noise from the engine bay
  • The smell of burning wires/rubber

Causes of a Bad Alternator

Wear & Tear

One of the most common reasons for your alternator to fail is simply old age and usual wear. With extensive use, internal components such as the bearings, stator, or the rotor itself can wear down to the point of failure. 

While alternators can be repaired after failing, the best course of action to avoid future problems is to have them replaced entirely. 

Fluid Leaking into Alternator

Being a sensitive electrical component, your alternator doesn’t mix well with liquids. If your vehicle is leaking oil, coolant, or power steering fluid around your engine, these fluids can make their way into the inner workings of your alternator. 

These fluids can cause major problems for your alternator, such as damaging components like the bearings or diode plate. If you notice any liquids on or around the alternator, you should have the leak dealt with immediately and possibly have your alternator’s electrical output checked in the process. 

Over-tightened Serpentine Belt 

Your vehicle’s serpentine belt (also known as a drive belt, alternator belt, or accessory belt) is responsible for driving several crucial systems, such as the power steering pump, water pump, and alternator.

If the serpentine belt has been over-tightened following a belt replacement or anything that requires the belt’s removal, there’s a chance that it will wear down or even break the alternator’s bearing. With a faulty bearing, your belt may not be able to spin the rotor properly and cause a lack of electricity needed to run multiple systems. In less severe cases, an over-tightened belt may lead to a noticeable squealing noise from your engine bay.

Serpentine belt on alternator

Salt and Water Corrosion

In environments where precipitation is common and road salt is used during the winter, your alternator may be subject to rapid wear from oxidation and corrosion, especially if it’s located at the bottom of the engine.

Alternators are built to be resistant to a normal amount of water, as your engine bay is far from airtight, but consistent contact with salt, water, and humidity can lead to corrosion of crucial internal components.

Electrical System Repair at Micro Import Service

If you’re looking for service for your vehicle’s electrical system or alternator in the Tucson area, trust the experts at Micro Import Service for stellar service at a fair price! Our ASE-certified technicians have years of experience working on all import makes and models. Call or schedule online with us today!