Remanufactured Vs Rebuilt Vs Repaired Alternators

An alternator produces electricity that your industrial vehicle’s battery stores. Since the alternator can only supply electric current when it is spinning, the battery is required to start the engine. If the alternator fails, often the vehicle will start, but will run only until the stored energy in the battery is depleted as the ignition, fuel pump and other components depend on a source of electrical current.

Signs an Alternator May be Failing

Sudden alternator problems may be easy to diagnose. Other times, the signs of a failing alternator are more subtle:

  • The engine turns over slowly or not at all.
  • The vehicle’s headlamps are dim and do not brighten when you rev the engine.
  • The charging meter is below 12V or above 14.5V or a charging system warning light is lit.
  • An engine belt is squealing or you smell burning rubber.
  • Rattling or whining sounds from within the engine compartment that change with engine speed.

If the vehicle shows any of these signs, take it to a battery vendor and ask for an electrical check. Your problem may be a worn or defective belt or a battery that is at the end of its life. If it is the alternator that is defective, then you must repair or replace it.


Alternator Repair and Replacement Options

Buyers are sometimes confused by the three “Rs” when it comes to getting an alternator fixed: repaired, rebuilt and remanufactured. To add to the confusion, some “experts” will say there is no difference between a rebuilt and a remanufactured part. This is not true. Each term indicates an increasing level of sophistication in the ability to restore a broken alternator and the reliability of the end product.


Repairing an alternator means that whatever parts are malfunctioning are replaced. A skilled repairperson might also replace parts that are near failure. This option can be the least expensive for the vehicle owner depending on the cost of the parts that need replacement. Only replacing a part or two in an alternator that has already failed may be no more than a temporary fix.


Rebuilding an alternator is a more involved process. The alternator is dismantled and inspected. Internal electrical and electronic components are tested. Parts that are known to have a relatively short life may be replaced without testing. Although a rebuilt alternator sounds comparable to a remanufactured or a new alternator in terms of reliability, everything depends on the skill and standards of the individual technician who performs the work.


Remanufacturers follow strict guidelines and procedures. They replace the voltage regulator, diodes, brushes and any other part that has failed or is likely to fail. Their testing equipment is state-of-the-art. They restore an alternator to original equipment manufacturer standards of operation. A Factory Authorized Remanufacturer is best in class among remanufacturing facilities and offers the longest guarantee for the product. They even incorporate design improvements made since the alternator was originally manufactured.

Can You Tell the Difference?

The quality difference between a rebuilt and remanufactured alternator can be vast while the price difference may be small. The most important factor for buyers to consider is the reputation of the facility performing the work. A longer warranty is a good indication that the facility has confidence in their product. A trusted mechanic can provide guidance as well, since he or she often has firsthand knowledge of the failure rate of alternators from different facilities.

For complete alternator units, component parts, repair kits and more, contact the experts at Elreg today.

Alternator photo credit to Matt under cc 2.0

Alternators photo credit to Laurie Avocado under cc 2.0