My service charging system battery light is on after replacing my alternator with a brand new one. It is not charging my battery.

My service charging system battery light is on after replacing my alternator with a brand new one. My alternator is also not charging my battery. What could be the problem
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
Hello, thank you for writing in. Several things may be going on. The installation of the new alternator needs to be verified, focusing on the electrical connections and the drive belt. Make sure the connections are clean, dry, and tight. Make sure the drive belt is routed properly and is tight on the alternator pulley (as it is what powers the alternator). If the installation was fine, you will want to make sure the alternator was not faulty from the factory. It is not common, but these issues have been known to happen. Most automotive parts stores can test the alternator off of the vehicle. If you would like more help with testing, contact our service department to schedule an appointment.

How to Identify and Fix Common car Problems ?

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It is possible that the problems that you have been experiencing with the bad alternators have damaged the battery causing it to be weak. This would make the Battery Light come on. It is also possible that there is a problem with the fusible link or the alternator fuse for the charging system.
Sometimes after a battery has been replaced there can be a few warning lights illuminated in the instrument cluster when the vehicle has been started. Most likely they will be a combination of the ABS, ESP and TCS lights however there may be others. The first thing to do is not panic – this is normal.
What`s happening when the battery/check charging system light comes on? Whenever this light goes on, it means that the vehicle is running solely on battery power. If the problem continues and your charging system fails, the battery won`t be able to recharge and it will soon run down, leaving you with a dead battery.
Generally not required,. if the alternator is replaced within a short time after the frequent discharge of the battery. However, if it was used for a longer time, the battery may need replacement as it may not be able to hold charge.
The question is, can a faulty alternator destroy a new car battery? The answer is that a bad alternator, does not always affect the car battery, especially if the battery is new. However, there are chances that the faulty alternator can kill your new battery.
The red battery light could indicate a problem with the alternator, battery or other parts of the electrical and charging system in the car. It could be a minor problem such as a malfunction rectifier unit, blown fuse or cabling short circuit.
If you want to perform a full reset, wait at least 15 minutes before reconnecting the battery to ensure all residual power has been drained. A full reset reverts your ECU to its factory settings and likely causes it to forget its learned ideal shift points and air-fuel mixing ratios.
What should you do if the battery warning light comes on? The first thing you should do is turn off any electrical systems in your car that you don`t need. That means turning off the stereo, air conditioning, heated seats and anything you may be charging in the car.
If this warning lamp lights up while the engine is running, it means that there is a problem in the charging system, usually that the battery has gone bad or the alternator has stopped working. Sometimes if your car or truck won`t start, you have a bad battery, one that can`t hold a charge.
This indicates that the alternator is not working properly. What is this? The most common cause of this problem is an alternator failure. Alternators are responsible for charging batteries in cars and other vehicles, and when they fail they can cause all sorts of problems with your vehicle`s electrical system.
Your battery light likely came on as a result of additional draw or amperage from your car`s charging system. Keep an eye on your charging gauge, but you should be fine. If you notice that you are having further problems, have the battery inspected by a professional in order to have any corrections made.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My service charging system battery light is on after replacing my alternator with a brand new one. It is not charging my battery.
ANSWER : Hello, thank you for writing in. Several things may be going on. The installation of the new alternator needs to be verified, focusing on the electrical connections and the drive belt. Make sure the connections are clean, dry, and tight. Make sure the drive belt is routed properly and is tight on the alternator pulley (as it is what powers the alternator). If the installation was fine, you will want to make sure the alternator was not faulty from the factory. It is not common, but these issues have been known to happen. Most automotive parts stores can test the alternator off of the vehicle. If you would like more help with testing, contact our service department to schedule an appointment.

is the ecm the problem if battery light is on and the alternator isn’t bad
ANSWER : This is likely a sign of a failing voltage regulator. This is a unit that regulates the charging of the battery by the alternator. In your case, it sounds like the voltage output from the alternator may be much too high resulting in overcharging the battery and burning up wires in the process. I would recommend having an expert from YourMechanic come to your location to diagnose and properly test your vehicle’s charging system.

Battery good, alternator good, brand new alternator cable, still not charging.
ANSWER : Hi There,
The first diagnosis of the bad voltage regulator is likely the cause of your charging system not properly charging the battery. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In some cases when a battery is too weak or damaged, it may no longer hold a charge for any length of time, in which case the alternator may be doing its job, but the battery is just simply too weak to hold a charge. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

installed new alternator and battery the alternator is charging the battery and the battery is maintaining afull charge but the ba
ANSWER : Hello. If the battery and the alternator are new and if it is verified that the alternator is charging then you have an issue with programming. When you replace the battery on this vehicle the computer needs to be reprogrammed to recognize it and to properly charge it. If this is not done then the computer will not turn on the alternator at the correct times an this battery light will come on. You need to have this programming done by a certified mechanic, like one from YourMechanic, who can come to you to [program the battery into the computer] https://www.yourmechanic.com/services/battery-light-is-on-inspection

Ok so i just got a use but like new alternator on my 2011 chevy cruze and a brand new battery
ANSWER : The voltage output of the alternator should be tested at the battery terminals while the engine is running. You should read output of 13.8 volts on up to maybe 14.4 volts but the value (and range, which is dependent on engine RPM) will depend on your Factory Service Manual Specification which the Mechanic will have on hand. You also have to look at the output while running various circuits. It could be that there is a short in one of those circuits which causes battery voltage to drop below the threshold at which the warning light will set. My initial suspicion would be the alternator is simply out of spec. What I would recommend is having a certified professional from YourMechanic perform an inspection of your battery and charging system which will identify the root cause of this issue you are having. Once the cause is understood, he or she will explain the repair strategy and cost. Please let us know how we can assist you further or if you have additional questions.

Has new alternator, new battery when started , motor dies when battery is disconnected…my mechanics are stumped on this
ANSWER : Hello.

If replacing those particular components did not correct the issue then the next thing I would look at is the vehicle’s voltage regulator. It appears that this engine’s electrical system is equipped with an external voltage regulator that functions, or malfunctions, independently of the alternator. The voltage regulator regulates power from the vehicle’s alternator, and can cause issues with the electrical system when it malfunctions. I would test it to see if it is functioning properly. It is a silver box that should be mounted somewhere in the engine bay, usually on a wheel well. A technician from YourMechanic can come to your home or office to replace your car’s voltage regulator if necessary.

Regards,
Eduardo

in my car battery warning light appearing while driving.so I have replaced both battery and alternater still light is on
ANSWER : As you may yourself have seen, there are many reports of this fault with the Civic, that is a battery or alternator is replaced only to have the warning light fail to extinguish despite checking every conceivable electrical possibility. Your only recourse is to have a certified mechanic go through that exercise with your car and that involves first attempting to "re-set" the light. If the warning light returns, the alternator output has to be carefully measured both loaded and unloaded. All terminal connections have to be verified including all grounds. Fuses have to be checked for integrity (continuity) and the possibility of shorts, in for example dash wiring, has to be checked. To request this repair, simply request an electrical components diagnostic and the responding certified mechanic will seek a resolution to this.

I have replaced the battery and alternator and the charging system light keeps popping on and then the car dies after a day or two
ANSWER : The problems you are describing do seem to lead me back to the charging system circuit. If the vehicle shuts down because of a dead battery, the problem has to be in the charging system as it is designed to maintain the battery charge while the vehicle is in use. Loose battery cables or corrosion like the technician said can cause problems as well. Consider hiring the aid of one of our mobile experts for a personal diagnosis of your charging system.