Bad Alternator Vs Bad Battery

An alternator can help replenish the battery in your car, but it can't keep it going indefinitely. an alternator caution, Keep a great electric battery charger. It is a misconception that if one battery goes bad it will ruin all the other batteries. I am thinking the replacement alternator is bad also Not likely. Here's how to do it: Turn off the car. To run a kick start CH without a battery and this alternator you need a Lucas capacitor from a 12 volt British bike. New alternator was not charging battery and my volt meter on the dash was low and then after 30 seconds it went to zero and check gauge light came on. It measures the voltage and cold cranking amps (CCA). The 50-amp alternator was added in 1973 when they added fresh air fans and other extra electrical items to the cars. Aside from a dead car battery, there are other signs of a bad alternator that aren't as, well, extreme. For the easiest alternator test, simply turn on the headlights to your lawn mower or outdoor power equipment. and subsequently that when the lights turn on the engine d. Then, with the engine running at around 1000 rpm, measure the voltage across the battery -- should be around 14 V, but I suspect you will find it lower. There are certain signs of a bad alternator to look for: While running the car, note the brightness of the interior lights. For example, if the battery has a RC rating of 100 minutes or 60 Amp Hours (C/20) rating, use approximately. Its within 1 volt Im pretty sure. Sometimes it can be difficult to tell if you have a bad battery or bad alternator. 5 volts, the alternator is trying to charge it and the battery needs to be tested further. If administration by syringe or intravenous injection is necessary, a vial should be used. However it could be a blown fuse or wire connection from the alternator to the battery. If it reads even lower, close to battery voltage or less, the alternator may be dead. The real problem may be a bad battery, loose or corroded battery cable connections. Dirty connectors? Bad battery? Bad cables? If so, do I buy the whole battery cable or just the connector at a car store? Sorry for all these questions, not really a DIY guy. I am thinking the replacement alternator is bad also Not likely. Your car's battery is its heart - when you have a dead battery, your car isn't going to run. • IG is the ignition input that turns on the alternator/regulator assembly. Any problems within the wires, cables or connections at either end can reduce or stop electricity from getting through. You can find this tutorial in Spanish here: Cómo Probar el Alternador (2001-2005 1. Make sure the alternator is tested (can be tested at an auto parts store). A bad voltage regulator can leave a vehicle sitting on the side of the road. How many kms has the car done? My alternator went at 300,000kms. if not then bad alternator or bad connections at alternator. The other possibility for a dead battery is a short in one of the cells, and this method won't work. Your XS650 must have a good charged battery to run, spark, and charge. battery was factory, and figured it was about time anyway, even though it still held up under the load test. If your car starts the battery is good, it has no role after that unless the alternator is bad but if the alternator was bad the battery would be dead. So I would ask how much power might a typical alternator be permitted to put into a car battery? I have a 1. The Battery (A bad or dead battery) The Starter The Alternator or Generator. Welcome to my forum! I will give you an insight on how to tell what is wrong with either your vehicle or a forklift when it comes to voltage. You may think it to be a battery issue and change it without running any tests, but a damaged alternator can destroy a healthy battery. If your battery is good, and you want to play it safe, charge the battery before running it with the good alternator. Might have a bad. Here are a few signs that your alternator might be going. In practical terms, if you disconnect the battery while running, the voltage will rise high enough to cause failures in many electrical devices. Or just let the alternator charge the. You can't judge alternator output from system voltage. If your battery is discharged to the point where it cannot start your vehicle, use a charger as soon as possible to make sure your battery gets fully charged. Are these the symptoms of a bad starter?. The alternator generates AC voltages, then diodes block one way and let power though in other way, that gives you some rippling DC but battery smooths this out. bad alternator, bad voltage regulator, bad connections between the battery and alternator. People often think that a dead battery should be discarded and pay huge bucks to buy a brand new one. The good news is that replacing a factory alternator with a high output alternator, in and of itself, isn't going to damage the rest of the electronics in your car, even if the new alternator is much, much bigger than the old one. A bad alternator will not properly charge the battery. I have a new battery, Battery cables, No wire. The battery will COMPLETELY effect running voltage and mimic a failed alternator (Bad cable connections too) Find more about the effect of battery condition to running voltage here. Test the battery again while the engine is running. An alternator can help replenish the battery in your car, but it can't keep it going indefinitely. If this happens, charge the battery out of the car to confirm it is still good. See our lemon odds and nada odds page to see vehicles with no repairs or vehicles with more than three repairs. The regulator and alternator worked properly and started re-charging the battery, but when I went to drive the car again I noticed that characteristic "whining" sound that comes from the regulator being in the "charging" position. With some simple troubleshooting you can get back on the road fast. Nothing bad battery related. But if you should discover in the middle of a trip that your engine battery is not being charged because the isolator is bad, you can get out a wrench and move the engine battery wire to the same terminal as the alternator wire and have a temporary solution to the problem. A "coach" battery powers the lights, furnace, water pump and other 12 volt devices in the coach. A voltage regulator sits between the alternator and the battery, translating AC to DC. Check the amperage output at the rear of the alternator and see if it is more or less than the amperage coming out of the battery's positive cable. There are two basic types of lead-acid battery charger: FLOAT chargers and 3-STAGE CHARGERS. Light still on, tested alternator (at battery) and alternator alternator tests BAD in car, tests good bench - EricTheCarGuy - EricTheCarGuy- Stay Dirty! Battery light on, tested battery and charged. It is the alternator that needs to be replaced, not the car’s battery. 80 to just over 14 volts. 5 Volts with everything on, then your alternator is not bad). A NiMH or NiCd battery is likely to deliver much closer to its rated capacity when it's powering high drain devices. Also, if the battery itself is bad, an alternator in working order won't be able to charge it. What Does It Mean If Your Seat Belt Won't Pull Out? August 30, 2019. It also provides power to the electrical and electronic devices in your car when the engine isn't running. Here's the design basis that Ducati used for sizing the system: Design Basis. connects to the rear of your alternator. At idle it only. Now the orignial Clie battery came with 800 mAh and the volts is 5. With a Q's heavy eletronics and all, I don't know if it's a good idea. When I turn the truck off and take the key out, the “alt” light stays illuminated on the dash and the. Trying to charge a battery with too few volts is just like trying to air up a tire with too few pounds of pressure. To check duel circuit flywheel alternator system, disconnect AC lead from the alternator to the lights. Think of an alternator like a cell phone charger, and your car's battery is the phone. ) DETERMINE CAPACITY RATING The capacity rating is located on the battery. There are certain signs of a bad alternator to look for: While running the car, note the brightness of the interior lights. Causes of a Bad Alternator. However, doesn't the DIC display the charging voltage? I'd think that a bad battery would cause the alternator to go to 14. Take some time to consider whether the starter is the problem so you aren’t faced with being stranded in the near future. When talking about the Ford 6. 7L Honda Civic) (at: autotecnico-online. If You See This. There are a couple of ways to test for a bad battery or starter. Sometimes it can be difficult to tell if you have a bad battery or bad alternator. For track applications there is a 2-circuit cut-off switch – one circuit for the battery and the other for the ignition & alternator. Test the battery again while the engine is running. Generator The Ultimate Grudge Match! By Don Wilson TECH DOCTOR DON WILSON has worked in technical capacities in the automotive, RV and marine fields and for the military since 1989 and has extensive experience in designing and troubleshooting onboard electrical systems. Honda CR-V Electrical Problems. As good as an alternator is at replenishing your car battery; it can only recharge it to the point that it has a decent amount of life left in it and is able to accept a charge. still work, though. I ran one car after it was transported back from a VOI with a battery that was almost totally dead. When the engine is off, the battery powers the lights and accessories. Just wiring up the alternator PLIS connector on a kit car build. I would strongly recommend getting one and carrying it with you. This is done by jumping full battery or full ground to the generator or the alternator field post. There is also a difference in size as alternators can fit into a small space, while generators are larger. Once you shut the engine down, the same battery will be providing power. but if this happens to you, have a look at these top three reasons before moving on to the rest. A greater difference of potential (voltage) between the battery's voltage and the alternator's output voltage will provide a faster charging rate. Learn how to give them new life with our step by step battery reconditioning guide. Here are some steps you can take to troubleshoot your car battery problems. However, doesn't the DIC display the charging voltage? I'd think that a bad battery would cause the alternator to go to 14. Doing this would allow you to check whether the alternator is putting out enough current to run the vehicle. The huge upgrade of this alternator over the 2G is a self-exciting, externally regulator that only required one cable between it and the battery to complete the circuit. Adding a 70 amp alternator is a fire hazard on those cars without a shunt. Inverter Vs. Clean battery posts and terminals. By the way, any rebuilt part is suspect. Check the. I jumped the battery and it starts right up. 5 volts, the alternator is trying to charge it and the battery needs to be tested further. This is shown in Figure 2. A bad or failing alternator can discharge your battery, cause issues with your car's electrical systems, or leave you stranded wh. 6 volts), the alternator is most likely bad and the car is running off the battery. This video is unavailable. Here are some ways to test your battery, and determine if it's bad. • B is the alternator output wire that supplies current to the battery. If the battery is 3 or more years old, chances are very high it's the battery. Best Answer: Alternator. Since the length of your PDA's wire inside the battery casing is difficult to know (unless you open the casing) let's just use a more common formula for Watts: (NOTE: DO NOT OPEN YOUR BATTERY'S CASING, EXTREME HARM WILL COME TO YOU) Watts = Volts x Amps. The cooked alternator you see below was made by manufacturer of the rather brash statement above. 2 Motorcycle tyre reviews Pt. "If you see the battery light on, it's really important to get it addressed," he says. The electrical system in a vehicle is more complex than most people realize. And it's not always easy to tell what the problem is when it stops working. If the battery is really weak or dead, the alternator cannot bring it back to life. Go back to town. So if the battery is bad, or connections corroded, bad bearings etc. I put it on the charge several times up to 15 so I could run the car. While all will claim to be particularly well suited to a energy storage purpose, all deep cycle batteries are not created equal, even within their own type such as AGM, Gel or Sealed Lead Acid. The alternator solves a lot of the problems associated with the generator by creating the charge current in the stationary alternator housing, and using the rotating part, called a "rotor" to generate the magnetism needed to induce a current. The diodes of the alternator can go bad, failing to transmit the required voltage. Before automatically assuming it is the battery that is questionable, check the plug ins on the voltage regulator. Symptoms Of A BAD Alternator. Either a bad belt, which needs to be replaced or at least tightened, or the automatic tensioner that keeps the belt taut may be malfunctioning. I have a 60 A alternator connected to a briggs mower engine and had to remove thr regulator, as the alternator would take all the engines power and bog it down,to a stall. A NiMH or NiCd battery is likely to deliver much closer to its rated capacity when it's powering high drain devices. Exercise bikes and elliptical machines can be powered by a battery or by an AC adapter. If you get a battery light the battery is bad. Replied by Wayne613 on topic battery/alternator or fuse/relay problem Before bothering with a diagram or the like, test voltage on the B+ terminal with a DMM if you can get to the back of the alternator (to check before the fusible link that protects the rest of your electrical system from a faulty alternator or any short on that line). Alternator is Not Working – A damaged or broken alternator could be the culprit. It is the job of the battery to provide the power to crank the engine and start the vehicle, however, it is the job of the alternator to make sure that the battery stays charged. One of the first symptoms of a bad or failing alternator is the need to jump start the vehicle on a regular basis. So before you throw out your current car battery and get a new one, you or a professional should run a battery test on it before you discard something that is still good to use. Also, visible corrosion on the battery's terminals is a clear indicator that you need to install a fresh battery. Take some time to consider whether the starter is the problem so you aren’t faced with being stranded in the near future. Occasionally, a symptom of this issue might be brighter lights, as the alternator produces more energy to overcome the resistance in a bad wire or a broken or loose connection. Generator The Ultimate Grudge Match! By Don Wilson TECH DOCTOR DON WILSON has worked in technical capacities in the automotive, RV and marine fields and for the military since 1989 and has extensive experience in designing and troubleshooting onboard electrical systems. What is a dead battery cell, what causes this to happen, and what are the implications? the good cells in the bad battery all needed water as they were being over. 2008 Volkswagen Beetle Dead Battery or Bad Alternator. The battery, alternator and fuel pump aren’t the only culprits when your car dies off you while driving. They'll check the battery with the car off to see if it's at or close to 12. I'd suggest pulling the battery and having it load tested. Also ,just because the belt is tight means nothing. Also on most modern cars, when the alternator goes bad, your battery light on the dash should turn on right away. "Alternators are used in automobiles to charge the battery and to power all the car's electric systems when its engine is running. The V-Star 1100 Charging System There is a lot of issues noted online about the V*1100 charging system. They do draw more amperage to get the same power. Buy LActrical HIGH AMP OUTPUT HD 95AMP ALTERNATOR FOR HONDA GOLDWING GL1500 GL1500A GL1500I GL1500SE GOLD WING ASPENCADE INTERSTATE: Alternators - Amazon. It measures the voltage and cold cranking amps (CCA). What should happen when you start up your vehicle is the ignition coil will take its power from the battery and relay it to the spark plugs. Keep a excellent Cheap Loan Online battery battery charger readily available always. Starting Problems? How to Tell If It’s the Battery or Alternator. So I or shouldn't I disconnect cable for one of the tests. are often greaty aggravated by the installation of a "remanufactured" alternator. You may be able to drive the car a short distance, if you can keep any unnecessary electrical systems turned off. Usually a bad or failing ignition relay will produce a few symptoms that can notify the driver of a potential issue. Extreme temperatures in both winter and summer play a large part in battery failure. Many people, even professionals, are quick to assume the battery is bad, but this can be a costly assumption if your failing alternator kills your newly replaced battery, too. Deep discharging of this type will. If it gets brighter, then the battery is most likely bad. If you live near one of our stores our automotive service staff will be happy to help you diagnose and fix such issues so you can get back on the road again!. Also on most modern cars, when the alternator goes bad, your battery light on the dash should turn on right away. Venting over time/life indicates an aging battery with one or more cells going bad and you will begin to see sulfation collecting around the posts. If the battery voltage decreased, this indicates the battery is discharging under the electrical load of the bike and the charging circuit is not working. Voltage Regulator if it just has a rectifier then the output is low and a charge current of say 3A is not going to do harm to a starting battery. It also recharges the battery. Without a good stator, your engine will run poorly or not at all. AutoZone tells me that the battery is just OK and the problem is somewhere else. Here's the design basis that Ducati used for sizing the system: Design Basis. An electronic battery test should be done, which gives more information than a standard load test. Having an expert test the alternator and battery together is the only way to know for sure if either or both parts need to be replaced. When you are diagnosing a problem in your cars charging system it is very easy to overlook the possibility of bad battery cables. So I took the battery in and had them test it. Just wondering if anyone is familiar with the signs of an alternator going bad. I truly WOULD start looking at the ignition switch as suggested; it has TWO contacts used for starting: 1 is for activating the starter relay which sounds like it is working fine. If the voltage is less than 28 volts ac, the alternator is bad. I was able to limp home with engine temp hitting 230 right as I pulled in. Alternator is Not Working – A damaged or broken alternator could be the culprit. 1999 Volkswagen Beetle Dead Battery. as for the alternator, it may have a bad regulator not allowing it to charge much above 12. Hook this lead to the hot lug on the starter relay. Why? Because an alternator that IS charging the battery will produce 13 (up to 14. Unsolder one leg of the diode if it is part of a circuit, otherwise the other components in the circuit may affect the results of the test. Other causes for a car failing to start are a bad starter or relay. Bad Alternator Sign #2: Weak or Dead Battery; A battery that seems to be weak or has died may mean your alternator is going bad as well. Float chargers also come in two versions - good ones and bad ones! A good FLOAT charger charges the battery at a constant current until the 'FLOAT' voltage (13. They will be able to give the alternator an electrical test to see if it is bad or if the battery itself is bad and needs to be replaced. Alternator bad? or battery? or ground? This is a discussion on Alternator bad? or battery? or ground? within the General Help forums, part of the LSx Technical Help Section category; Sometimes after starting my car i notice the battery gauge is fluctuating and i can see my headlights slighty flickering. Your alternator fails prematurely due to being over worked. Alternator issues can be a big hassle if you suddenly find yourself stranded because your vehicle’s electrical system is no longer working up to spec. com FREE DELIVERY possible on eligible purchases. One of the first symptoms of a bad or failing alternator is the need to jump start the vehicle on a regular basis. So if the battery is bad, or connections corroded, bad bearings etc. Started fine, ran for a few days, then it started getting weaker and weaker when turning the key over. Get to know just how the charger hooks as much as your. What Does It Mean If Your Seat Belt Won't Pull Out? August 30, 2019. If it reads even lower, close to battery voltage or less, the alternator may be dead. Learn how to give them new life with our step by step battery reconditioning guide. If administration by syringe or intravenous injection is necessary, a vial should be used. First look for a short or bad connection to the alternator stator coils. Alternator - In case you have come outside, got into your vehicle and turned the key, simply to discover that nothing happens you'll need to find out the cause. No bad connections or issues whatsoever per mechanic and the alternator is just fine. The 50-amp alternator was added in 1973 when they added fresh air fans and other extra electrical items to the cars. Bad positive battery cable connections at the power distribution center (usually. The field wire is the one closest to the positive output stud on the back of the alternator, and should be connected to a switched hot battery source (but not the lead to the distributor, otherwise the engine will not cut off with the ignition switchguess how I know that, LOL). 5 volts, might be lacking amperage output, or could have a bad rectifier. If you have a bad car battery, that is a fairly easy fix, but you could have other problems that are limiting your car battery from creating the desired amount of voltage. Sympton: Battery slowly goes dead, but ammeter sometimes shows a positive charge. They will be able to tell you if it's the battery, alternator, voltage regulator, etc. Watch a video on how to perform battery, alternator and charging system test. The battery volt gauge is jumping between 14-15 volts while running. With the correct socket, loosen up the alternator adjustment to be able to remove the alternator belt. How do you know if your alternator is bad on a 2003 Mazda Tribute? Car just went dead while drivingaccelerator - Answered by a verified Mazda Mechanic. I am running the boat battery wiring from the switch to my two batteries. A bad or failing alternator can discharge your battery, cause issues with your car's electrical systems, or leave you stranded when you need to use your car. As a deep cycle battery can be quite an investment, you’ll want one that will last the distance. If you see a modern vehicle that measures the life or temperature of the battery, it is bad practice to use the positive and negative battery terminals to power aftermarket accessories. While this is one option to retrieve. This is usually a bad diode in the alternator, less often a bad regulator. Checking for a Bad Diode. It is much easier to replace the battery than the alternator. If your alternator fails, your battery will lose its charge since the alternator won't be able to keep it charged up. The symptoms of a bad alternator and a dead battery can be very similar. I thought it was the battery so I got a new Platinum from Advance. That’s why, oftentimes, the alternator, not the battery, is the problem in the first place. - Mocking Sep 14 '16 at 0:27. If you see good voltage then bad battery. You should honestly be seeing 14V, regardless of load. With some simple troubleshooting you can get back on the road fast. Honda CR-V Electrical Problems. My thanks to Danny at South Carson for diagnosing my alternator. If this happens, charge the battery out of the car to confirm it is still good. Just wondering if anyone is familiar with the signs of an alternator going bad. Disconnect the battery, measure the battery voltage and write it down. What do U guys think? Is it the battery or the alternator?. Especially one that's overcharging itself, because that means it's got a short somewhere, and eventually has the potential to overload your battery. DO NOT USE WING NUTS 37-895387 3486 13. Dealer checked over the jeep while I waited and then told me the alternator is bad. 8 volts with no load) & I start engine & measure the current from alternator charging battery I get around 45 amps? If I add a 45 amp load the alternator output goes to 90 amps, why does the battery charging by itself only charge at 45 amps?. Output Current. If your battery goes dead, have the alternator checked when replacing the battery so it doesn't happen again. Saw another article by a EE HAM radio operator indicating that silicon dielectric grease had advantages over petroleum. still work, though. If your alternator fails, your battery will lose its charge since the alternator won’t be able to keep it charged up. 1) Check to make sure the battery is charged to 12. Looks like the easy test is to test battery with engine off at 12v then start it up and turn every thing on and see if it is at 14v. it is more of a problem because of the higher current. My 99 Jeep Cherokee XJ and 97 Buick Park Ave are older cars that orignally came with flooded batteries. The regulator and alternator worked properly and started re-charging the battery, but when I went to drive the car again I noticed that characteristic "whining" sound that comes from the regulator being in the "charging" position. Obviously, batteries sometimes fail on their own--but a bad alternator can actually cause the battery to drain because it's failing to recharge it. How to Know If It's Battery or Alternator (Bad Alternator Vs Bad Battery) Having a bad battery or bad alternator can be really vexing especially if you can't tell which one it is. If the battery is dead, it does not mean this is the only problem you now face. Refer to engine installation manual for size requirements. This means it's important to distinguish between a weak battery and a bad alternator. If it was a bad starter i thought it wouldn't start at all once you turn the car off, but mine came back on as if the 5 min drive charged the battery enough to start the car or turn the radio on not both. Today, most cars have a single maintenance-free 12-volt acid battery (in the photo). Bad Alternator Sign #2: Weak or Dead Battery; A battery that seems to be weak or has died may mean your alternator is going bad as well. This wiki has been updated 15 times since it was first published in May of 2016. Check bulb in headlight ( do not touch the glass part of the head lamp). and you have tested 2 other alternators, are they also the cs144 ? can you ta Charging Issue with New Battery and Alternator - Page 2 - Toyota 4Runner Forum - Largest 4Runner Forum. Once you have narrowed down the issue with these tests, you can perform electrical tests on the alternator itself to determine for sure whether it is malfunctioning. As a deep cycle battery can be quite an investment, you’ll want one that will last the distance. While this is one option to retrieve. It's possible to get correct voltage readings and still have a bad alternator due to bad diodes, this mode of failure can only be detected by a shop using a scope. Occasionally, a symptom of this issue might be brighter lights, as the alternator produces more energy to overcome the resistance in a bad wire or a broken or loose connection. it won't start b/c your battery is too weak. The car doesnt start if I leave the radio on or have the interior lights on when the car is off. Hi all just wondering what problems can a bad stator cause but a bad battery or connectors and wiring A lot of bikes have a three phase alternator and have a. So the Watts would be:. Past few months on occasion I've smelled a slight "electrical burn" smell after pulling the LR3 in the garage and it seems slower to crank over- the battery is good to my knowledge- like maybe it's not getting charged properly?. 5 volts - if not, remove the terminals and check it again to verify that something isn't draining it while it's not running. However it could be a blown fuse or wire connection from the alternator to the battery. The battery is actually a load on the charging system. Also, the 3" adjuster bolt may be seized, so be ready to make a run to the hardware store for a replacement. In case you find that the car doesn’t start when the ground cable is removed from the battery, the alternator is not in the working condition. A shorted battery or reversed terminals could cause the diodes to draw too much current and. I had my go bad with the battery going dead this thursday. First look for a short or bad connection to the alternator stator coils. For instant 12 Volt charging, just install and connect your main charging wire. Signs of a Bad Car Alternator. Use a SHIELDED alligator clip for post attach-. • B is the alternator output wire that supplies current to the battery. Obviously, batteries sometimes fail on their own--but a bad alternator can actually cause the battery to drain because it's failing to recharge it. with good battery start car and check charging system If voltage reads below 13volts possibly the alternator is bad. Basically, your battery gets the engine going, but once it's on, the alternator takes over and can, in theory, continue running the car without the battery's help. What's New Homepage Motorcycle News Hayabusa News Hayabusa Pictures Hayabusa Store. All the lights, etc. Here is a short run-through of how lead-acid batteries work. The fact of the matter is an. I will check the wiring at the alternator tonight. Unsolder one leg of the diode if it is part of a circuit, otherwise the other components in the circuit may affect the results of the test. Think tnt with battery acid, toxic fumes, alkaline, and hellafied flames involved here if it blows. This has its advantages – it provides a totally independent means of charging the start battery, as well as providing a level of built-in redundancy in case a battery or alternator is to fail. 3 - check out the flimsy battery terminal made from steel. A new alternator will recharge battery but since it is well below charge from running it to the point that if you jump it and take cables off and it starts to die out getting the battery fully charged is the best thing to do. The fact that after it started running. If the motor is not charging the battery it will go dead. However, doesn't the DIC display the charging voltage? I'd think that a bad battery would cause the alternator to go to 14. Don't rely on your alternator to do the work of a charger. That's why, oftentimes, the alternator, not the battery, is the problem in the first place. The symptoms of a bad alternator and a dead battery can be very similar. While your battery stores up the electricity your Jeep needs to start up and keep running, your alternator actually powers all the electrical parts of your Wrangler. If the alternator is bad, the battery may not be capable of starting the engine. Alternators are NOT chargers. If your car will not start and you think you have a bad battery, alternator or starter, have your car inspected by a professional mechanic. Make sure the alternator is tested (can be tested at an auto parts store). My truck wouldn't start and the batteries were down to 5. with a fully charged reading of under 12v the battery is bad. Several factors determine how long your battery will last, for example weather conditions, vehicle type and driving habits. Figured I got a bad alternator so took the new one off, returned it, got a new new one and it is doing the same thing. To see how frequently Honda CR-V problems occur, check out our car reliability stats. Pep Boys’ Winter Prep Service Package can help limit the wear cold weather can put on your car. If it gets brighter, then the battery is most likely bad. I'm a little confused. If an alternator is overloaded, it may overheat and fail (check for aftermarket sound equipment that may be overloading the stock alternator!). If the car dies, alternator is bad. A battery load tester such as a Sun VAT-40 is used. A voltage regulator will limit the maximum amount of voltage from a power source and prevents a device or alternator from. 1999 Volkswagen Beetle Dead Battery. This translates to a fault with the alternator or battery. If this is the case, then I wouldn't have been able to drive my car down to the dealer with both a bad alternator fuse and bad battery. If the starter is good, the last likely culprit is a bad alternator. Car Type, Year & Mileage? How Old is your Battery? Without more details it's hard to say. If you disconnect the battery and the car conks out, you don't know if it conked out due to insufficient alternator current, or whether the resulting transients caused your ECU (the car's computer, which controls fuel mixture, timing, and much more) to spit out bad data, shutting down the car. An Alternator Check: To determine if the alternator is generating the proper amount of current and voltage to keep your battery charged and your electrical systems performing as expected. The battery voltage should increase once the engine is started, as the alternator supplies additional power (see the photo). 3 - check out the flimsy battery terminal made from steel. So I took the battery in and had them test it. That's why you need to check the battery before checking the alternator. Check bulb in headlight ( do not touch the glass part of the head lamp). It is the job of the battery to provide the power to crank the engine and start the vehicle, however, it is the job of the alternator to make sure that the battery stays charged. If it was a bad starter i thought it wouldn't start at all once you turn the car off, but mine came back on as if the 5 min drive charged the battery enough to start the car or turn the radio on not both. Changing out your battery is a fix that you can usually do on your own. No need to pull the battery or anything else. Mainly that the battery gets real hot, may appear to be bloated, and no longer works. How many kms has the car done? My alternator went at 300,000kms. These higher voltages allow the battery to be charged faster. I still have the stock alternator, and I plan on doing the big 3. Then you have to select an output size based on your electrical demands, battery size, and the pulley type you have.