What happens if you have a new alternator and the battery is not charging?

What happens if you have a new alternator and the battery is not charging?

The alternator in your car is an integral part of your vehicle’s electrical system. If you have a new alternator and the battery is still not charging, then you definitely have some kind of a problem with your battery that you’ll need to address immediately.

What should I do if my alternator keeps dying?

The alternator is essentially a generator and it keeps your battery charged while supplying additional electrical power for the other systems in the vehicle. If you have a new alternator and your battery keeps dying on you, then there’s definitely a problem that you’re going to need to look into.

How can I tell if my alternator is working or not?

If you’re not 100% sure, you can use a multimeter, or a voltmeter, to check the current coming from your battery. Attach the positive lead to the positive battery terminal, that’s the red one, and then the negative leave it to the black terminal. With the engine off you should be getting a reading of 12.5 volts on your multimeter.

How long can a battery last without an alternator?

A good alternator and can last well over a decade, sometimes as long as 15 to 20 years. However, if an alternator does fail on you then you’ll know it fairly quickly as your electrical systems will fail soon afterwards. The charge in your battery does not last long without the alternator there to keep it running properly.

What does it mean when your alternator is not charging?

If the alternator is not charging the battery, you will have a red “ALT” or “charge” sign on your dashboard. This means that your battery is no longer being supplemented for power by the alternator. You will need to recheck the wiring because the light could also be faulty.

Is there a fuse between Alt and battery?

Harbor Freight will occasionally have their voltmeter on sale for less than $2.00 there IS a fuse between the alternator and the battery!!!!!! There is conductivity between alt and battery post. so that is not the problem, dead alternator. fun trip home. “jump” about 30min… drive… “jump” for about 40min… drive… did get home though.

What happens when the alternator of a car is dead?

The alternator and the car’s battery work hand in hand. A good battery should give you service for the next five years before its lifespan ends. If your battery is dead, then it will not give power to the car’s alternator. The alternator normally lasts longer than the battery.

How can I tell if I have an alternator problem?

To differentiate an alternator problem from the battery, you will need to use a voltmeter to check for voltage. First, turn off the engine and check the battery voltage. A fully charged battery should have a reading of 12.65 volts. Next, turn on the engine and recheck the voltage. You should have a reading of 13.5 to 14.5 volts.

What causes an alternator to go over base voltage?

If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

Do you need a DC charger for a Smart alternator?

The vehicle has a battery monitor attached and regulates the charging. However as we all agree if you want 100% charging of the leisure batteries you need a dc-dc charger as a simple split charge relay is nit suitable for smart alternators. MOLL battery issue. Stop/start…regen…smart Alternator…

Can a bad alternator Fry a new battery?

The flip side is that a defective alternator can fry a battery, also. So replacing a battery and having the new one go bad soon afterward might mean the alternator was bad to begin with. A depressingly large number of people don’t test the charging system after replacing a battery.

Why is your new alternator not charging your battery?

The most common reason for an alternator not charging a battery is because of a bad alternator or battery . You can easily test the voltage by connecting a voltmeter to your battery while the engine is off.

Why is the alternator not charging?

– Broken Belt or Pulley. The belt and pulley produce the mechanical power which gets converted into electrical energy by the alternator. Your belt can easily break if it gets stretched out too much, causing it to snap apart. The pulley can also get damaged after a while. In either case, the alternator will no longer be able…

How do I know if my battery or alternator is bad?

Signs of a bad alternator. If the above steps reveal that the battery is working, it’s time to take a closer look at the alternator. There are certain signs of a bad alternator to look for: While running the car, note the brightness of the interior lights. If the dashboard gradually dims, the alternator is likely at fault.

Why does an alternator overcharge?

Typically, one of two problems cause overcharging alternators: poor battery condition and failed regulators. When a battery is already getting old and worn down, the alternator may run extra hard to increase its charge. However, overcharging of any type still triggers battery damage,…

How can I tell if my alternator or battery is OK?

As with most electrical issues, if you know the battery or alternator is OK (because you had it tested), then diagnosis comes down to tracing and testing for continuity from one portion of the circuit (s) involved to the next.

What to do if your alternator won’t charge your battery?

Make sure you ground your multimeter, and put the power side to the stud that is coming out from the alternator (should be nut holding your wires that go to your battery). If your getting 13.5-14.5V there then the connection between the alternator, and battery is bad.

A good alternator and can last well over a decade, sometimes as long as 15 to 20 years. However, if an alternator does fail on you then you’ll know it fairly quickly as your electrical systems will fail soon afterwards. The charge in your battery does not last long without the alternator there to keep it running properly.

The alternator is essentially a generator and it keeps your battery charged while supplying additional electrical power for the other systems in the vehicle. If you have a new alternator and your battery keeps dying on you, then there’s definitely a problem that you’re going to need to look into.

What should I do if my alternator is not working?

The solution is to check your car’s manual for the particular fuse that controls the alternator and replace it. In some cars, you might also find another small fuse to the alternator’s control—usually a 15A to 20A fuse. An alternator does usually has 3 or 4 wires to it to function properly.

Is the alternator the only thing that powers the car?

Many people assume that the car’s battery is the only thing that powers all electrical components in the car. But, this is not true. The alternator plays a vital role in supplying power to the car’s AC, recharging the battery and ignition.

What should the voltage be on a new alternator?

The wait time was 1 day. I installed the new alternator myself and went back to AutoZone to test it. Again, getting the same error “VOLT REG FAILED”. I also ran across a Haynes vehicle manual that states that the voltage should be around 13.5 V – 15 V, but it is not always this way.

What causes your alternator not to charge?

There are several different problems that can cause your alternator to stop working. Your car’s alternator charges the battery by generating power with a pulley and belt system. If the belt that controls that system snaps, stretches out or breaks, the alternator will stop working, and the battery will not charge.

What are signs of needing a new alternator?

  • Warning Light. Many automobiles have a battery or alternator warning light on the dashboard.
  • Load Test. Conducting a load test will indicate whether or not your alternator needs to be replaced.
  • Voltmeter Test. You can test your charging system with a voltmeter.
  • Other Signs.

    Why would a good alternator not charge a battery?

    The alternator is powered by several different wiring mechanisms. If a wire is not attached properly, becomes detached or is inadvertently cut, the alternator will not have any power. If the alternator is not getting any power, it cannot turn the pulley and belt mechanism that charges the battery, and the battery will not charge.

    Is it normal to have 15.5 volts in alternator?

    Seeing 15.5-15.7 volts is normal on the new GM charging systems. May I ask, what led you to replace the alternator in the first place? I would have the charging system tested by a shop with a decent scan tool to monitor the desired voltage vs. the actual voltage.

    Is the alternator on my Buick overcharging?

    I have a 2006 Buick LaCrosse with the 3.8 L motor. Last week I found out that the alternator was overcharging (charging at around 15.5-15.7 volts.) The car has 72000 miles on it.

    The alternator in your car is an integral part of your vehicle’s electrical system. If you have a new alternator and the battery is still not charging, then you definitely have some kind of a problem with your battery that you’ll need to address immediately.

    Many people assume that the car’s battery is the only thing that powers all electrical components in the car. But, this is not true. The alternator plays a vital role in supplying power to the car’s AC, recharging the battery and ignition.

    If you are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the battery is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring.

    To differentiate an alternator problem from the battery, you will need to use a voltmeter to check for voltage. First, turn off the engine and check the battery voltage. A fully charged battery should have a reading of 12.65 volts. Next, turn on the engine and recheck the voltage. You should have a reading of 13.5 to 14.5 volts.

    The alternator and the car’s battery work hand in hand. A good battery should give you service for the next five years before its lifespan ends. If your battery is dead, then it will not give power to the car’s alternator. The alternator normally lasts longer than the battery.

    Why does my alternator cut off while driving?

    I just had the alternator replaced, but my car cuts off while driving. If your vehicle is losing battery voltage (i.e. your battery light is on) the problem may be your battery. You have a new alternator, so if your battery is bad, it won’t hold the charge from the alternator.

    Why does my car not start with a new battery and alternator?

    With a new starter, battery, and alternator (assuming you have not drained the battery attempting to start it), the starter should attempt to crank over the engine. If the starter does not make any noise when the key it turned to crank over the engine, you have an issue with the fuses, or the circuit.

    I just had the alternator replaced, but my car cuts off while driving. If your vehicle is losing battery voltage (i.e. your battery light is on) the problem may be your battery. You have a new alternator, so if your battery is bad, it won’t hold the charge from the alternator.

    The solution is to check your car’s manual for the particular fuse that controls the alternator and replace it. In some cars, you might also find another small fuse to the alternator’s control—usually a 15A to 20A fuse. An alternator does usually has 3 or 4 wires to it to function properly.

    What makes alternator go bad?

    Causes of a Bad Alternator. One of the most common problems of a faulty alternator is a loosened belt. The diodes of the alternator can go bad, failing to transmit the required voltage. The bearings on which the alternator rotates can also be at fault and hinder the alternator from providing an optimal performance.

    How do I know if it’s the battery or the alternator?

    Check the Alternator. Test the alternator to make sure that it can start up the battery. If the battery is working properly and nothing is wrong with it, then it’s the alternator that will more likely cause a problem. Try to start the engine and listen carefully, if it produces a “whining” sound, it may be the alternator.

    Why is my alternator not working in my Lexus?

    With the headlights, blower motor, and radio on this should change very little. If the voltages begin to drop into the low 13 volts or below (usually rapidly as the loads increase), a failing alternator is to blame. Seen above is a factory re-manufactured alternator next to a failing unit removed from a 1998 GS400.

    What to do if your Toyota alternator fails?

    As Eden Prairie and Chanhassen’s independent Toyota and Lexus repair specialist, we hope this helps a DIY or curous owner understand Toyota and Lexus alternator failure a bit more. If you think you have a charging or starting system issue, CARspec offers no cost battery and charging system checkout, so give us a call at (952)426-4798 today!

    Why is my alternator not working on my new Lexus?

    Either the replacement alternator is defective or there is some issue in the charging circuit. Either way something is causing a battery drain. Jump the battery and see if the engine starts. If it does, it’s a clear indication that the alternator is faulty and needs to be replaced.

    How long does it take to replace alternator on Lexus RX350?

    Next, check the ground to alternator case. If nothing wrong can be found, replace the alternator with one of a different brand or install an original alternator. How long would it take to replace a Lexus RX350 alternator? Job book rate is around three hours.

    Why does my alternator not charge my battery?

    If the light burns brightly a parasitic draw is draining the battery. This generally happens overnight when the car is shut down and the alternator does not charge the battery.

    What should I do if my alternator is draining my battery?

    Check the battery and alternator and if they are good, check for a parasitic draw. To do this, turn off all electrical accessories and features and close all doors. Now remove the negative battery terminal and connect a test light in series. If the light burns brightly a parasitic draw is draining the battery.

    Why isn’t my alternator charging my battery?

    6 Causes of an Alternator Not Charging Worn out carbon brushes or damaged alternator. The most common reason why your car is not charging is actually because of a worn-out or damaged alternator. Broken Serpentine belt. Faulty fuse. Wiring issues or connectors. Damaged car battery. Engine control module error.

    Is the new battery and alternator testing good?

    New battery and alternator testing good. Why? My battery light came on awhile ago, so I replaced the battery. It now will come on every and now and then. Just randomly I will be driving and it will come on and then a minute later go off. I have got alternator tested at Autozone and they said it was good. I have also tested it myself.

    Why does my alternator not charge on tickover?

    On checking the battery voltage was low – 11.8V engine running. Battery was replaced about 1 month ago.After much investigation discovered that the alternator does not ‘kick in’ until I rev the engine to approx. 3000rpm – it then charges away happly for the rest of the journey (at around 14.5V) even on tickover. Has anyone seen this problem before?

    What will happen if you put a wrong alternator?

    When the wrong alternator has been installed in a stock vehicle or if the pulley has undersized dimensions (causing extra alternator rotation), the charging supply will be higher than the demand and cause an overcharged state. High performance or racing alternators should not be installed on stock passenger vehicles.

    Why is my car battery still not charging?

    If you are sure that your alternator is working properly and yet your battery is still not charging, then it’s possible that you have a bad voltage regulator in your vehicle. The voltage regulator keeps the right amount of electrical power flowing through the various electrical systems in your vehicle.

    If you are sure that your alternator is working properly and yet your battery is still not charging, then it’s possible that you have a bad voltage regulator in your vehicle. The voltage regulator keeps the right amount of electrical power flowing through the various electrical systems in your vehicle.

    What causes a battery light to come on after a battery change?

    This is especially true in late-model vehicles with their more sophisticated internal diagnostic systems. There are usually two things that cause the battery light to come on after a battery replacement. The most common is a loose connection – perhaps a terminal connector was not tightened sufficiently when the battery was replaced.

    What should I do if my alternator does not work?

    In these cases, your alternator would fail and your battery would not charge. If you have a bad alternator, look in the owner’s manual to see where the alternator fuse is in your car and check to see if it is blown. Alternators use the mechanical power of a belt and pulley to generate the electrical energy for the vehicle.

    Is it possible to kill an alternator with a dead battery?

    Urban myth… but it is so pervasive that it may well prevail into the 22nd century. Even most automotive “experts” insist it is so. It is not difficult to design an automotive charging system that will protect the alternator/generator from high loads.

    Can a bad car battery cause an alternator to not charge?

    In theory a car can run only with the alternator charge, but this can cause heavy voltage spikes and other strange symptoms so this means that a bad car battery can cause an alternator to not charge also. Cars are increasingly coming with modern electronics.

    The flip side is that a defective alternator can fry a battery, also. So replacing a battery and having the new one go bad soon afterward might mean the alternator was bad to begin with. A depressingly large number of people don’t test the charging system after replacing a battery.

    How long does it take for an alternator to fully charge?

    Only if it is about ready to fail anyway. It does put a very high load on the alternator and will make it quite hot. It can take several days for the battery to fully charge under normal driving. The extra load can take out an old belt due to slippage.

    Why does my car battery charge but not charge?

    Alternator problem occur because the alternator charges the battery when the car is running. If you jump the battery and it only remains charged for a little while, that’s a positive sign of a faulty alternator. However, it’s very important to have your car thoroughly inspected before you replace anything.

    Can a negative battery test a bad alternator?

    Some may recommend running the engine with the negative battery cable disconnected to test the alternator. However, this is not a good idea because it could damage the electrical system of your vehicle and cause greater problems. Fixing your battery or alternator can be an expensive repair.

    Can you drive a car with a faulty alternator?

    Faulty diodes can easily be replaced, but you will need to dismantle the alternator. It is impossible to drive the car with a faulty alternator. While it is the work of the battery to power the electrical components in the car, it cannot do this alone.

    Why does my car not start when I jump the alternator?

    If jump starting gets your engine started and running, but the car will not start again once you turn it off, the battery is probably the problem. In this case, the alternator is doing its job of keeping the battery going once it has been jumped, but the battery can’t hold a charge when the alternator is shuts off.

    If you have a new alternator and the battery is still not charging, then you definitely have some kind of a problem with your battery that you’ll need to address immediately. That’s because the alternator works in conjunction with your battery to ensure that all your electrical systems have the power they need to function.

    How does an alternator work in a car?

    Any electrical component in the vehicle will only draw the current required to operate. The ECU in some cars adjust the field input to the alternator based on the given load of all electronics. On some cars this is all sampled and done 100% in the alternator’s internal voltage regulator.

    How many volts should I have on my alternator?

    Remember that measuring them is not always correct because you have to load test wires that are half broken or have a bad connection. You should usually have 12 volts on one of these wires, and the other one goes to the battery light on the dashboard. If you have a 3rd one, it does often go to the engine control unit.

    How does an alternator charge a car battery?

    Remember that an alternator is an electrical component responsible for charging the car battery. The alternator basically converts mechanical energy into electrical energy, which then charges the battery and all the other car’s electrical components.

    How to troubleshoot an alternator and charging system problem?

    If necessary, adjust the belt with the help of your car owner’s manual or repair manual. Inspect the belt for signs of cracks, cuts, shiny spots, deterioration or other signs of wear or damage. Change the belt and belt tensioner at the manufacturer’s recommended interval. 2. Check for Wiring Problems

    Can a high output alternator damage the car’s computer?

    Batteries will buffer most damage caused by out of range voltage issues. Even a stock alternator is capable of massive voltage output, but is regulated to around 14V through the voltage regulator. High Output alternators are regulated in the same manner.

    How is the alternator related to the ECU?

    And some cars like Chrysler, Dodge, or Jeep the ECU completely controls the voltage and field input. But with all of these systems the loads of the car will be powered by the alternator. All these systems will continue to adjust field input to power loads, no matter the given load.

    What should my alternator voltage be when I start the car?

    The voltage reading should be between 12 and 13 volts. You can automatically assume there’s a battery problem when the reading is lower. In the event your battery’s good, start the vehicle and get the engine up to 2,000 RPM. This will put a lot more demand on the alternator.

    If your not getting a reading from there you can check your output from your alternator. Make sure you ground your multimeter, and put the power side to the stud that is coming out from the alternator (should be nut holding your wires that go to your battery).

    What are the main functions of an alternator?

    The main functions of an alternator are to generate electricity for the electrical components of the vehicle and to charge its battery. The alternator produces this electrical energy by converting mechanical energy. Looking for a good online repair manual?

    Why does an alternator need to be charged?

    Even if you had a new car battery and were lucky enough to turn the engine over, it would probably run for about 10 minutes before the power cuts out. The alternator is necessary to keep the battery recharged and to alternate the electrical current throughout the many components of your vehicle to keep them powered.

    How can I tell if my alternator is charging the battery?

    Use your multimeter (if you don’t have one get one). Turn it to dc volts put your leads on your battery (with the car running), if your alternator is charging it should read from 13.5V-14.5V (thats a good charge). If your not getting a reading from there you can check your output from your alternator.

    Is the alternator still running off the battery?

    Now i hooked up the voltage tester to the battery with the new alternator and the car still seems to be running off just the battery (at about 12 volts).

    Do you need a multimeter to check your alternator?

    A multimeter measures voltage as well as other electrical properties such as current and resistance. You want to measure voltage when you’re checking your alternator. Check the battery first. The battery is needed to start the vehicle, which, in turn spins the alternator at sufficient speed to keep the battery charged.

    How can I tell if my Toyota alternator is charging?

    I’ll have to double check, but it should only be around 300 mA once the fuel pump is off. To do this, disconnect one of the battery terminal wires. Turn the ignition to the ON position and turn your radio and all lights off including your dome light.


    As with most electrical issues, if you know the battery or alternator is OK (because you had it tested), then diagnosis comes down to tracing and testing for continuity from one portion of the circuit (s) involved to the next.


    Can a loose tensioner cause an alternator to fail?

    Nevertheless, if the tensioner wears out, it can cause alternator problems (loose belt or worse, the belt can totally fall of the alternator pulley). Broken or damaged wires This happens mostly in older cars duo to material fatigue of the electric installation.