Can a defective alternator discharge the battery

What if the alternator is defective?

Defective alternator - how do you know? Causes, Signs and Consequences

In today's cars, a three-phase generator works as an alternator (LiMa) and generates electricity through electromagnetic induction. When the engine is running, the LiMa supplies all electrical consumers with energy and charges the starter battery at the same time. If the alternator is defective, this supply is insufficient or interrupted. The car can continue to drive with a defective alternator, but the power consumers in the car then fall back on the reserves of the battery. If this is empty, the car with the defective alternator comes to a standstill due to a lack of electricity. Then only a repair or replacement with a new alternator will help. At FairGarage you will find workshops near you that can replace the alternator at a fixed price. You can find out more about the workshops, their range and prices online. The workshops listed here only use parts of original or identical quality. You can arrange your desired date for replacing the alternator online.

The control lamp reports the defect!

Many drivers only concern themselves with the alternator when the charge indicator light lights up in the car and does not go out again after a few seconds. With this sign, the vehicle reports that the battery is no longer being charged. Then the only thing that helps is a visit to a specialist workshop. In the first step, the workshop checks the charging circuit and the starter battery. In this way, the workshop can narrow down the cause of the fault.

When can the alternator break?

A defect in the alternator is more of an exception in the life of a car. Modern LiMa offer a long service life. As long as the generator is properly powered, it provides enough energy for all electrical consumers on board. The charging voltage is a kind of yardstick for the function of the alternator. Before anything is done on the alternator in the workshop, it is therefore completely measured.

How do you recognize a defective alternator?

Different causes can be responsible for the defect. If the charging voltage is too low, the alternator is defective and must be replaced. If the LiMa is driven irregularly, this can be noticed by signs from the engine compartment, e.g. squeaking noises. These can occur due to a defective pulley or a poorly tensioned V-belt. A broken alternator bearing can also cause problems.

Other signs of a defective alternator

The signs and symptoms that indicate a defective alternator are not always clear. Basically, any problem with the power supply can be an indication that the alternator is broken. This includes starting difficulties and an almost permanently empty starter battery. But these symptoms don't have to be related to a defective alternator. The cause can also be the battery, as it can no longer be fully charged. A defective regulator can also affect the power supply in the car.

Typical weak points of the LiMa

The power supply around the alternator has four typical weak points: This is the alternator itself, which can usually break at higher mileage. Then the mentioned regulator or also called charge regulator can break. The cables and plugs can also corrode or break. This leads to contact problems and thus also to a disruption of the power supply. Finally, the V-belt or V-ribbed belt can cause problems. A defective belt tensioner is sufficient here. Then the tension of the belt is too low. The belt then slips under load.

The weak points of the LiMa at a glance:

  • the alternator itself
  • the charge controller
  • the cables / connectors
  • the V-belt / V-ribbed belt

The four well-known sources of error

If the V-belt squeaks, it is too loose and prevents the frictional connection between the engine and the alternator. In this case, the alternator itself is not defective, but can provide little or no power to the vehicle electrical system and the battery. Defective cables and plugs are also a possible cause of insufficient charging current. If the alternator itself is defective, the generator's coals are often used up. The only thing that helps here is changing the alternator. As a rule, the alternator in a car only becomes a problem much later than the battery, cable / connector or charge regulator.

Common cause of the defect - the charge regulator

The cause of the defective alternator is far more common than the other sources of error in the charge regulator. The charge regulator can be used to measure whether the alternator is delivering enough current. Values ​​below 13 volts indicate problems. The only way to do this is to visit a specialist workshop. Remote diagnosis is not always effective on this subject.

With the defective alternator to the workshop

A defective alternator is an issue that cannot be postponed. You should go to the workshop as soon as possible if you notice any irregularities. This will avoid a breakdown on the way. If the alternator is revealed to be the cause of the problem in the garage, it should be removed and replaced on site. The starter battery is also checked, which is not infrequently affected if the alternator is defective. In the past, alternators were dismantled in the workshop and defective components were replaced. Today, for cost reasons, brand-new or completely overhauled alternators are installed. At FairGarage you will find workshops near you that can replace the alternator at a fixed price. You can find out more about these workshops and what they have to offer online. The workshops listed here only use parts of original or identical quality. You can arrange your preferred date for replacing the alternator online.