One of the most common faults of a car’s electrical system is alternator failure. The alternator is the engine’s component which transforms the engine’s revs into electrical energy and recharges the car battery. Since all cars need electricity for spark plugs, headlights, car management systems and various other components, when the alternator fails, cars stop very soon. Today, we will tell you all about alternators and how to repair and replace them.
What is an alternator and how does it work?
The alternator is an engine component designed to turn mechanical energy into electrical energy and recharge the car battery. The alternator is hooked to the engine and powered by a timing chain or belt. While the engine is running, it spins the alternator and produces electrical energy. The alternator powers the car’s electrical systems while the car is working, and it is a crucial component in proper functioning of the car as a whole.
Modern cars with numerous electronic safety systems, creature comforts and infotainment displays rely heavily on alternators for power supply. However, despite its relative simplicity in construction, alternators started to see the use in domestic models only in the 1960s. Before that, cars used dynamos which proved somewhat inefficient.
The dynamos worked in a similar manner and used the car’s revs to provide the electricity. However, the simpler concept produced less power than needed, and it was only enough for primitive cars with no power options, radios, or modern headlights. As soon as the car industry started putting those components into everyday cars, dynamos were replaced by alternators which proved to be a better choice and today are part of every single vehicle produced in the world.
What are the signs of a bad alternator?
Alternators are known to stop working without a warning, and when that happens, your car stops recharging the battery which can cause failure to start or cause the engine to stop working in total. However, there are a few signs that the alternator is near its end of the road.
The first sign is the change in intensity of your headlights. Since a failing alternator is causing variations of voltage, the headlights can go from dim to really bright. Second sign to look for is the smell of burning plastic which indicates burned alternator wire or internals.
When you notice those signs, chances are that your alternator is done. But if you replace it as soon as possible, it could save you the additional expense of getting a tow truck because, yes, you will eventually get stranded by the side of the road with a broken alternator.
In most cases, the failing alternator will drain your battery and leave you with a dead car. However, alternators are known to cause even worse problems. We will now explain two main reasons of alternator failures and its solutions.
Since the alternator is a fairly simple device which consists of a bearing connected to the rotor, there are few things that can go wrong mechanically. The first one is the bearing which is connected to the engine via the timing belt or chain and rotates the rotor inside the alternator housing, producing electricity. The bearing can fail due to poor quality, lack of lubrication, or wear, but if that happens, the alternator will fail to turn and fail to produce electricity.
Unfortunately, the bearing that is not turning will put stress on the timing belt and eventually cause it to snap or twist. This is extremely dangerous since it can cause enormous damage to the rest of the car. The same timing belt powers the rest of the car’s systems like water or oil pump. If it snaps, the engine is doomed.
However, if the rotor fails, the alternator will still be turning but it will not provide the electricity. This is the less dangerous scenario since the failing rotor cannot harm the car as much as the alternator bearing. In some cases, it can do some damage to a car’s electrical system, but if you act fast enough it is likely that no wires will be burned.
New, used or refurbished alternator?
When replacing the alternator, most owners of common domestic models are faced with the decision of using new, used, or refurbished parts and we will explain the difference.
A new part is, obviously, the best but still the most expensive choice. However, it comes with a warranty which means that you are good for a long period of time.
Used alternators are the cheapest solution but not such a good idea since they can also fail at any moment, bringing you back to where you started.
The refurbished ones are a good choice since the alternator is a relatively simple part and lots of shops can easily refurbish it, replacing the internals with brand new or repaired ones. In most cases, reconditioned alternators have a 1-year warranty which is good enough for most users.
How do you replace/repair an alternator?
After you have positively determined that the alternator is broken, you can proceed to remove it from the car to replace or repair the part.
The first step is to disconnect the car battery, loosen the timing belt, and disconnect the wires. Then you can remove the alternator housing from the brackets and physically remove the part from the car. As always, different cars have different mounting solutions and removal procedures so be sure to have a service manual and follow the instructions.
Replacing the alternator bearing is pretty straightforward as well as replacing the rotor. Of course, if you want to replace it with a completely new alternator, you just repeat the steps and mount it right back. On most modern vehicles, skilled mechanics can perform this task in two hours.
Alternator Repair Costs and Labor
As we said before, prices of replaced alternators can go from $200 to $600 with parts and labor depending on the vehicle’s type, brand, and model year. Older cars are cheaper and easier to work on which affects labor costs. Newer models are more expensive and some brands require special tools to reach the part. In most cases, replacing the alternator is not that complicated and you can do it by yourself in your driveway with standard tools.
Of course, different cars have different spec alternators and prices can go up for rare and luxury models and foreign cars. If you want to save money on alternator repair, consider doing the work yourself but consult the professionals and pay attention to safety.