How To Extend The Life Of Your Alternator
Alternators have evolved from relatively simple devices into complex power-generating components. Regardless of their complexity, Toyota alternators last for years. But aging and general wear-and-tear may eventually mean that they need to be replaced.
This can be a costly exercise. So, we got some valuable advice from the Car Care Nut on the basics of Alternator design and how to look after them to extend their service life.
Alternator Basics
In essence an alternator is a power generator. It generates electricity by creating a magnetic field via a spinning rotor. The rotor is connected to the drive belt, which gets power from the crankshaft.
The alternator has a rectifier to convert AC (alternating Current) into DC (Direct Current). A Capacitor then evens out the power supplied to the vehicle’s electronics.
The regulator maintains a steady 12 volts from the alternator as the engine speed fluctuates.
Its function is to charge the battery and power various electrical systems while the engine runs. The battery stores power used to engage the starter motor and power electrical devices when the engine is not running.
Basic Alternator Components
The basic components of alternator design and construction include:
- Voltage regulator
- Rotor
- Stator
- Pulley
- Rectifier
- Bearings
How Has The Alternator Changed Over Time?
Most Toyota alternators have had a similar design for years, and their basic functionality was very similar. The introduction of onboard computer systems and more advanced engine designs has necessitated several changes to cope with the added power demands.
One development that has happened in recent years is that the engine computer or ECU (Engine Control Unit) has taken over control of the regulator. This has resulted in more precise power level control and quicker response times.
An alternator gets it's power from the engine. This increases drag which has a negative effect on performance and fuel efficiency. With the ECU controlling the regulator, the alternator’s power draw can be optimized to improve overall efficiency.
Another development that smooths out the electrical power delivery and lessens the load on the engine is a one-way clutch. This lets the rotor spin at a different rate from the pulley, resulting in less drag on the engine and a smoother idle.
How To Extend The Service Life Of Your Alternator
- Never drive with a flat battery – the alternator can get damaged trying to constantly charge it
- Don’t let fluids or leaks enter the alternator – This can damage the components
- Do not clean the alternator with water or brake cleaner – both can cause serious damage
An alternator is designed to keep a battery charged at the right level, but it was never intended to be a high-powered battery charger.
"Alternators are meant to maintain a healthy battery; they are not meant to charge a dead one."
- The Car Care Nut
Compared to any other electrical device, the starter motor draws the most power from the battery. Once the engine is on, the alternator tops up the battery and keeps the rest of the electrical systems powered.
"The battery is the number one thing that usually kills alternators. "
- The Car Care Nut
If the battery has a very low charge, or has run completely flat, it will draw a lot of current from the alternator. This severely strains the alternator and will eventually shorten its lifespan.
While some German makes have sealed alternators, most Toyota designs are open to aid with cooling. If oil, water, or other fluids leak onto the casing, they can easily damage the components, leading to premature failure.
When cleaning the engine bay, make sure to cover the alternator to prevent water from seeping into it. If you want to clean the alternator, avoid brake cleaners and use electronic cleaners instead. Ideally, the Car Care Nut recommends that any engine leaks be taken care of quickly, as the only way to properly clean an alternator is to disassemble it.
The Main Symptom Of A Failing Alternator
Image Credit: The CarCareNut
Diagnosing a failing alternator can be tricky, as several symptoms can also be caused by other components. The Car Care Nut narrows it down to one main symptom that is the most important to be aware of: a very distinct whining noise.
"You hear that loud whining noise that goes up and down with the engine speed? That's your first sign that the alternator is complaining and it’s time to replace it."
- The Car Care Nut
If your alternator stops charging the battery, the battery warning light will come on your dashboard. If you see this light, it means that the battery is running all the onboard systems and you need to get the car checked right away.
"You see that battery light, stop driving."
- The Car Care Nut
A less common issue can be a faulty rectifier. If one of the diodes in the rectifier become faulty, the power supplied to the engine will fluctuate. This can cause all kinds of issues with the onboard electronics.
OEM Alternators From Olathe Toyota Parts Center
As the Car Care Nut explains, an alternator constantly has a lot of load going through it and will eventually wear out. Most cars that cover high mileage will need one replacement alternator over their lifetime. Following his tips will prolong their lifespan, and he closes his video with the most important advice of all:
"Don’t buy aftermarket alternators."
- The Car Care Nut
The Car Care Nut always recommends OEM replacement parts. Buying aftermarket parts for a complex electrical device like an Alternator can result in electrical issues and big repair bills. For even more information on alternators, read our comprehensive buyers guide.
Always choose genuine OEM Toyota and TRD Performance parts from Olathe Toyota Parts Center.
We have a full range of Toyota parts, including alternators, battery components, and starter motors.
As part of a Toyota dealership centrally located in Kansas City, we carry a huge supply of parts. We back every part we sell with a Toyota unlimited mileage 12-month warranty. We ship quickly to both the East and West coasts. Use our free online VIN lookup to be sure you're ordering the right alternator for your vehicle.