How to avoid problems that may cause the alternator failure?

If we talk about classic vehicles where the main driving force is the ICE, then in such cars, the alternator is a major power source while the battery starts the engine and maintains a constant voltage. Therefore, it is important to have knowledge about the alternator weak spots and potential problems. It’s highly advisable for any car owner to have an idea about measures extending the alternator service life. 

Let’s start by identifying the sources of malfunction:

• unavoidable natural wear and tear;
• environmental negative impact;
• human factor.

Most common alternator faults 

When it comes to alternator weaknesses, the year of vehicle manufacture should be considered. Today they use small diameter commutators in alternators. It helps to reduce their wear and tear: the brushes and commutator-and-brush assemblies are quite low-wearing. This doesn’t apply to the old alternators where the brushes are often the major cause of failure. Sometimes a failure is caused by mechanical wear resulted either from the friction of brushes against the surface of commutator contact rings or from the contact burnout.  

Last generation alternators are equipped with pulleys with freewheel clutches. This assembly is not specifically reliable as 100 thousand operational kilometers is a life limit for a freewheel clutch.  

Almost all modern alternators are equipped with digital voltage regulators that continuously exchange information with engine control units. Such voltage regulators are not reliable and often fail. On top of that, their faults can vary and diagnostics requires the use of special equipment.

Faults of alternators of different types

In most cases, it's corrosion that causes an automotive alternator malfunction. An alternator acts like a vacuum cleaner in relation to dust, moisture, and other agents sucking them in and driving through. The problem is that not everything that is sucked in is then thrown out – something may be left inside. 

Corrosion damages the alternator without any possibility of its further recovery. It should be noted that technical fluids penetrating the alternator interior are one of the major causes of corrosion. 

Effect of loads on the alternator service life

A daily load affects the life of the alternator as well. It’s obvious that at higher loads, the alternator's temperature raises which leads to overheating and thus, to the alternator breakdown.  

Failure may happen when the alternator charges the battery and supplies power to other electrical consumers at the same time. This is a cold season problem. 

A car owner must know that when it’s happening, the alternator is operating at its limits wasting rapidly its resource. Modern alternators don't have any extra reliability margin when it comes to mechanical and electrical overloads.

Influence of a human factor on the alternator operational life

Jump starting from a donor vehicle with the engine of the dead car running, is an extreme alternator overloading. The alternator operating condition is similar to a short circuit. 

Warning! The alternator is not intended to be jump-started from the donor vehicle when the engine is running. This will become a death sentence for any alternator.  

Such methods of alternator quick check (used very long ago) when either the clips are removed from the battery of the idling vehicle or the alternator positive power cable is attached to the unpainted metal part of a vehicle are prohibited for use in modern cars. 

Rotor bearings wear and tear is another cause of the alternator failure. Such a failure may result from improper tension of the drive belt. When a manually tensioned drive belt is overtightened, the bearings suffer overload that shortens their service life. When the belt is undertightened, it will slide down the pulley causing wear both to itself and the working surface of the pulley.   

To protect the alternator from ingress of technical fluids, vehicle pipe and unit leaks should be eliminated without a delay. If the engine washing is required, the alternator and starter should be wrapped up in a waterproof material.      

Water and salt won't penetrate the alternator if there is protection installed under the engine and when the bonnet has a sealing. Plastic protection can be easily broken or damaged. Sometimes, car owners dismount it on their own to facilitate the vehicle maintenance.

Effect of a battery on the alternator condition

The condition of the battery affects the condition of the alternator. The majority of car owners use the battery until it completely loses its function. No one ever thinks about the effect of the battery on the alternator. Timely replacement of the battery will save you money on the alternator repair before its due time. In case the battery has been fully discharged, a stationary charging device should be used for it recharging instead of the alternator. 

The quality of the battery is another thing that should be taken into account. Sometimes the battery has been in use for only one year while the jars have already been closed on to fault. A faulty battery will lead to the alternator burning out. 

Let’s summarize

1. The alternator life is 4-5 years or 100 thousand operational km on the average. 
2. The key enemy of any alternator is corrosion. The corrosion causes damage to the alternator without the possibility of its recovery.
3. The quality and condition of a car battery have a significant impact on the alternator. 
4. Old methods of alternator diagnostics as well as, a jump-starting of a dead battery is a road to alternator death and its subsequent replacement.   
5. Continuous monitoring of the vehicle state is a fundamental of failure-free operation of both the alternator and vehicle itself. 

How to extend the alternator service life?

• Monitor the battery status and performance. If the battery is fully discharged, use special devices to charge it.
• Don't jump-start the car with its engine running. It is better to use a special starting device. 
• Don’t diagnose a car on your own.
• Keep the engine room clean. Rectify leaks.
• Install additional bonnet seals and engine protection when required.

Observance of these simple rules will extend your alternator service life.