Basically, the whole charging system makes sure that there’s always enough power on the car for the engine and accessories to run. If the car isn’t charged properly or the charging system can’t maintain a proper charge, you’ll see the Charging System Failure message.
In this article, I’ll go over the various components of the charging system, as well as possible remedies, based on what has likely failed.
What Does the Charging System Failure Message Mean?
If you’ve seen a warning message about charging system failure with a thumbs-down icon for the battery, then you have a problem with your vehicle’s charging system, and your alternator may have stopped charging the battery. This could be due to a faulty or bad battery, alternator, voltage regulator (that regulates the voltage produced by the alternator), and/or connectors.
If your vehicle isn’t charging the electrical system, you should be aware that your vehicle will eventually just shut down, and you will be stranded on the side of the road. Take this message seriously.
Charging System Failure Causes
One of the more common causes of a charging system failure could be a bad alternator or bad voltage regulator inside the alternator. It could be as easy as a broken serpentine belt or a blown fuse.
Here is a more thorough list of what could cause a charging system failure:
#1. Bad alternator.
The alternator is in charge of keeping the battery fully charged and any other accessories running. If the alternator fails, there is no way to charge the battery while the car is being operated.
The voltage regulator could also go bad; the voltage regulator is usually located on or even inside the alternator, but in some cases, it could be better to go ahead and replace the entire alternator. If the voltage regulator fails, the alternator cannot send the required amount of voltage to charge the battery.
#2. Broken Serpentine Belt.
The alternator is driven by the serpentine belt. Even if the alternator is working properly, if the serpentine belt fails, then it isn’t going to run.
When the alternator isn’t running, you can’t charge the battery. Although you may think the battery is dead, it may only be a broken belt that needs replacing to charge the battery up again.
#3. Blown Fuse.
Everything that runs in a vehicle requires electrical power. This power is delivered through a system of wires and fuses.
Like in your house, a fuse can blow at any time. It’s usually not that hard to replace a blown fuse and start charging the battery again. Look in your owner’s manual, and look for fuses for the alternator and charging system.
#4. Bad Wirings.
Other than the fuse, any number of the connectors or wires maybe be damaged and it’s possible the connections are just dirty and need to be cleaned up.
The major hassle in finding the repairs is finding the fault. If you aren’t good at working with the electrical systems, this diagnosis may be cumbersome.
#5. Bad Battery.
The battery might be responsible for all of the problems you’re running into. If the battery is old then you should look into replacing it.
When the battery is going dead you can usually tell because it will dim the headlights and make it seem like the accessories are not working normally either.
#6. Bad ECM.
On a lot of cars the alternator is controlled by an engine control module, and if the ECM has an issue, it could cause the alternator not to charge.
However, bad ECMs don’t happen too often, so it really makes sense to check other things.
How to Fix Charging System Failure Message
#1. Measure the voltage.
The first thing you wanna do if you’re having issues with the charging system is measure the voltage with a multimeter. Start the car engine and let it idle, and then turn on the headlights and wipers. Once that’s done, locate the battery and measure the voltage between the positive and negative terminals of the car battery.
You’ll wanna see something above 12.4 volts, and it’ll be even higher if you rev the engine. If it’s low voltage, you definitely know there’s some issue with the charging system, and need to keep on diagnosing the car. If it’s good voltage, you may have an issue with the instrument cluster on your car that is simply giving a false warning signal.
#2. Replace Belt.
If the drive belt breaks or wears out, it can’t turn the alternator. If the alternator is not working, the battery won’t charge, and electronics won’t work. The belt can also slip if there is a loose bearing, which will cause the charging system to fail.
Most drive belts last between 75,000 and 100,000 miles. However, if the belt is inspected regularly, you can discover issues before they happen. Replace the belt when it shows signs of wear.
#3. Fix Faulty Wiring.
Lots of wires and harnesses make up the charging system, and they all need to be good condition for things to work well. Often when there is a worn wire or connector, it will create problems for the entire charging system. The hard part of this situation is that it can be hard to find a faulty wire or connector.
One of the things to look for is corrosion on the battery terminal connections. Corrosion on battery terminals can affect the batteries ability to charge. If you are having a problem, it is a good idea to clean all of the connections and look at the wires, again if you see something that looks worn or bad, replace it.
You will also want to inspect the fuses that I mentioned earlier, if you find a blown fuse, change the fuse.
#4. Check and Swap Out Alternator.
Some people don’t know the alternator has gone bad until they put the new battery in, and then the new battery dies! The alternator has to be able to charge the battery and keep the car running. As the alternator dies, it can no longer meet the requirements of the battery or the electronics.
A lot of the time an alternator goes out because of the voltage regulator. Most alternators last for about seven to ten years or 80,000 to 150,000 miles without a problem.
They are pretty expensive, so we need to make sure it is diagnosed correctly before we switch them out. Sometimes, it is possible just to switch out just the voltage regulator or any other parts inside the alternator.
To properly diagnose it, you will need a wiring diagram, a multimeter, and some decent electrical knowledge. There is also an old trick where you can tap the alternator with a hammer and if it starts to charge the system, the alternator has gone bad.
#5. Replace Battery.
As a battery gets older, it will not be able to deliver the electrical demands of the vehicle. A weak battery will cause poor battery chemical actions, some of which will ever cause the voltage to drop. When this happens, the light will turn on and let you know it is time to replace the battery.
An old battery will show several symptoms that state that it is going to fail. There will not only be difficulty in starting the car, but the headlights and electronics will not function as well.
You will often notice intermittent power failure. If you notice that the battery looks funky, no matter how much power it is putting out, you should replace it.
#6. Check/Update ECU.
Moving on! If you can’t really see anything wrong and you’ve gone through all the other items, it is time to consider the ECU being defective and that action can actually happen, it is not too common (it is more common on older cars) but it can happen.
The Electronic Control Unit (ECU) of the car monitors all the voltage and power running through all the electrical systems of the vehicle, so if it is bad too much voltage can send the alternator and battery and possibly everything else in the charging system to send all the electric charging through the wrong system ruining these components.
You will need to use your code scanner to see the history and you may find that if it is the ECU, you will most likely get other lights on your dashboard beside the charging message.
In some cases, the ECU can be flashed or reprogrammed but sometimes it will need to be replaced. Either way, you are looking down the path of an expensive repair so it is probably worth it to go have the car properly diagnosed because you probably don’t have the ability to tackle this type of repair.
Cost to Fix Charging System Failure
Generally, it might cost you between $50 and $1,000 in repairs for a charging system problem. Replacing a fuse, voltage regulator, or connection will probably be your cheapest bill.
Diagnostic costs can be particularly painful, especially if you have a technician assessing your system on a whim (ie, labor charged by the hour) and may require them to spend time finding a damaged wire or defective connector.
And if you’re driving a luxury model, expect to incur the higher cost of replacing the more expensive parts and getting a technician to specifically look at your make/model.
Can you operate your vehicle with a faulty charging system?
No. If you notice a charging system failure warning on your gauges, you need to address it as soon as you can. Another day is better than no days at all, because a charging system failure caused by a bad alternator can quickly become a dead battery with a car that won’t start.
How do I know if my alternator fuse is bad?
The easiest way to tell if your generator fuse is bad is to measure it with a multimeter. In most cases, you can also pull the fuse and inspect it visually. If the fuse is bad, you will see the small piece of bad metal in the center is broken.
How do I know if my alternator is charging?
The only way to know if the alternator is charging or not is to measure the voltages with a multi-meter. Start up your engine, turn on the headlights, use the wipers, and let the car idle.
Then take a measurement at the are of negative terminal at the battery and positive terminal at the battery. If you see a volts are less than 12.4 volts, your alternator is failing.
How long can I drive with a Check charging system message?
Hey, if you notice a message on your dashboard that says “check charging system,” you really shouldn’t drive the car anymore. If the charging system is faulty, your car can lose power at any moment, and the car engine can fail on you.