How To Test Alternator Out Of Car

How to Test an Alternator Need to test your alternator? We are a team of ASE certified mechanics that have created this guide for you so you can save money or at least see what you are paying for when taking your car in for repairs. however, ever since i bought it and installed it, after about 1 days not using my car my car battery goes 100% flat. The multimeter then displays the voltage drop when the test leads are connected across a diode when forward-biased. There are some sure ways you can tell if your battery is bad by simply taking a good look. Connect the current probe to the alternator B+ output lead. It is for those who do not have a multimeter nor the knowledge of using one. Car Battery or Alternator: How to Tell Where the Problem Lies January 27, 2012 Almost all of us have experienced the problem where either your car battery or alternator just conks out, and you can't make out which one to replace. So, you'll want to check for the below signs to determine if it's just the battery or. The alternator's job is to produce electricity and charge the battery. How to test a car battery alternator, or spark plugs could be behind your vehicle's refusal to start, it's most likely that your battery is zapped. So now, thanks to your posts, I’ll give baking soda a whirl. Open the hood and observe the alternator belt's condition, along with its tension. A loose drive belt can cause an. 6 volts or above. Most shops can bench test your alternator. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. How to check the alternator with multimeter. No Probs, to make it easier, just test the output at the battery, not sure on the specs of your alternator, but it should put out close to 13. The bad alternator will also cause some unbearable noise from the car. You will hear a clicking noise while attempting to start the car, and the engine will have difficulty turning over. An alternator then tops off the battery's charge and powers all of your electrical accessories while the vehicle is running. I suggest that with an obvious lack of knowledge you should take the alternator to an automotive electrician who will have a proper test rig and the means to. Dimming Lights The alternator by itself can be the cause of dimming lights, fading radio, and/or stalling. Look to the alternator for problems. Car Battery Testing & Voltage It's important to test your battery and electrical system regularly, not just when it's starting to show signs of weakness. To check the alternator without voltage regulator: With the fat red wire hooked up to the battery (or starter bolt), unplug the wiring harness from the voltage regulator and jump the green wire to 12V and start the engine. Online Shopping at a cheapest price for Automotive, Phones & Accessories, Computers & Electronics, Fashion, Beauty & Health, Home & Garden, Toys & Sports, Weddings & Events and more; just about anything else Enjoy Free Shipping Worldwide! Limited Time Sale Easy Return. My car alternator runs at 16 to 16. When the engine spins the alternator around, the alternator induces an AC voltage that is converted to DC and used to charge the car's electrical system. Next, if the alternator is considered to be the problem, then he or she will test the output. The alternator is a pivotal piece of machinery when it comes to your car, truck, or SUV. But that doesn't rule out the alternator. To find what amperage your alternator is, you must first understand the relationship between volts and amps. Is the alternator charging the battery, check the output of the alternator 3. I recently changed my alternator, bought it second hand at scrap yard. 6 volts or above. To test the fuse, set the DMM to the DC voltage function and connect the black lead to a good ground, then probe both sides of the fuse for 12 volts DC. Fully charged automotive batteries should measure at 12. when you start the engine or accelerate, the belt should not squeal or flap. Alternator replacement can be done at a car dealership, an independent repair shop, or car-repair chains like Pep Boys or Sears. Other things might be causing these failures, but it's worth taking it to a trusted auto repair service to have it checked out. Our DIY article on how to test a Honda Accord alternator is broken up into three different tests. Consider replacement: Your car battery has passed the battery test but the result was a borderline pass, showing the battery's coming to the end of its life. If the battery holds a charge when it's not connected to the car - something is draining the battery far faster than the computer memory and digital clock. Also check for corrosion as this will inhibit the alternator from charging properly. Battery testers range from simple models that test how much charge is left in the battery, to more complex devices that test the battery's capacity for charge accumulation and potential issues that might impact its abilities. If it's worn out, get it replaced. The alternator is, thus, a very vital component of the car as it converts the engine’s mechanical energy into electrical energy. Car goes out of warranty in May 2014 and July 31, 2014 car alternator fails in traffic on way home from hospital. If it does, the brushes may be worn to the point that they don't exert enough pressure on the commutator. What are the basic test for an alternater with an ohm meter ingram alternator - Answered by a verified Auto Mechanic We use cookies to give you the best possible experience on our website. I just had to repalce the alternator on my rig and the parts guy was lost on what one it was suppose to have as there were two listings, fortunately buy comparing the the two on the bench it was determined to be of course the more expensive one as the electrical connections were slightly different and the clocking was a 180 degrees different. You might be asking how can I tell if the alternator pulley is clutched. YourMechanic can also test your battery to find out if it’s the reason why your car won’t start. You will hear a clicking noise while attempting to start the car, and the engine will have difficulty turning over. So now, thanks to your posts, I’ll give baking soda a whirl. Car starts but my headlights are dim at low engine speeds. Testing output on a Lucas ACR alternator. Doing this would allow you to check whether the alternator is putting out enough current to run the vehicle. Dear Tom and Ray: To do a quick check on an alternator, I was told that you could start the car and then remove the negative battery cable. In most stores, we can also test voltage regulators, control modules, coils, throttle position sensors (TPSs) and other engine management components. One tool you will need is a multimeter, if you are not familiar with how to operate a multimeter, check out our handy How To here. closed so the courtesy lights aren't on, check to make sure you haven't shorted any of the brown wires to earth/ground. 2) Connect a Voltmeter Directly Across the battery Terminals. Alternator. A voltmeter is another device that can figure out the voltage of a circuit for you. By taking out more than you are putting in. Literally just installed a brand new Altenator and my battery is great Condition but for some off reason m y car dies out on me every once in a while like o me a day most of the times if im l icky every otyher day or so but I have a code p0021 and I'm aware of that buyt I also need to put in a new sensor for the bank 2 on my Nissan Maxima 03 se anything so me one can help me out why this. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. Signs that the alternator is going bad include dim lights, odd smells, a weak or dead battery, unusual sounds, or a warning light. Re: Off the car Alternator test? You probably need to activate the excite line to get the rectifier pack to chuck out some Jolts, ask Kane he has had some funand games recently with alternators and may know which line, there are differing alternator types fitted accross the smart range that don't all operate the same though. Alternator Output Test. 2v but it should give you an idea. Its purpose is to monitor the system voltage, and increases or decreases the charging rate,. The diode inside the alternator can act as a ground when bad and will basically suck out the battery power like if you left your headlights or interior dome light on. It was probably only 1-2 min. Grand Caravan Crew 3. How to convert 6 volts to 12 volts. Our DIY article on how to test a Honda Accord alternator is broken up into three different tests. (see figure 5) A good fuse will show 12 volts on both sides. When the smoke clears, that "simple test" could end up costing you several thousand dollars for new electronics. Within caring read more about obtaining the response he wanted (me to try out longer along with him) than about how he behaved, he experienced the result of losing his basketball for 2 days and watching his new objective go abandoned. This test eliminates both the regulator and the harness, making it easier to isolate your investigation to the alternator. How to identify your GM Internally Regulated Alternator Delco Remy (System Integrated) SI alternator were used on GM vehicles between 1969-1988. Often old or worn out alternators ground themselves internally causing a short. 6 volts DC output at rated alterna - tor current output. The engine starts but dies. The labeled diagram of car engine shared here is one of the best free car engine diagrams you can find. Amateur rebuild - Regulators - Alternators - Troubleshooting - Photos The Bosch alternator is set up with a nice removeable modular voltage regulator and brush assembly that can be replaced fairly easily by the amateur hack like myself (or. It says alternator ripple tests. Park car on level ground - Make sure that your car is parked on a level surface if possible and switch the engine off. That means the alternator is pumping out the juice. Did you know a car alternator can be turned into a generator with a little know how and persistence? The car alternator's role is to produce electricity for your vehicle. If this is your first visit, be sure to check out the FAQ by clicking the link above. The Alternator. Measure the deviation with a ruler. When your car is running the alternator helps to power the different electrical systems in your car and keep your battery charged. 5, it's a good bet the alternator is good. These pictures. Check the alternator drive belt or serpentine belt: Look for proper adjustment. To check an alternator, pop your vehicle's hood and hook up a voltmeter to the car's battery by connecting the red lead to the positive terminal and the black lead to the negative terminal. There's also another way to check the alternator manually. Now that you know what you should expect to see in terms of rated amperage, you can test your alternator to determine if you're receiving an acceptable amperage. You may have to register before you can post: click the register link above to proceed. A bad alternator will not properly charge the battery. A standard car or truck alternator is electromagnetic-- meaning that some of the electricity produced by the unit must be used internally and sent to the armature through brushes and slip rings to make the magnetic field. You should not do this in order to test the alternator by seeing if the car still runs or by checking the voltage at the battery. Then, disconnect the main engine cable connection to the electrical block. Different variations of Alternator and Battery are used on different models. Test the Alternator Diode To check for a bad alternator diode, you may want to reset your voltmeter to the lowest possible AC voltage scale setting. This warning light may be a Check Engine warning, or it may be a Bad Battery warning. Connect the meter leads to the battery terminals and look for 13. I decide to take the battery to O'reilly and have them check it out, thinking it might have a bad cell, it checked out ok, so during some reading on the net that I did they said an alternator for a 2003 Escalade which is a 145amp alternator would bolt right into my car, so I picked one up, went home took the Mechman out and installed that one. Further guidance When the engine is running, an alternator generates electrical energy to supply the vehicle’s on-board electrical systems and replace the battery charge consumed during cranking. Last week I found out that the alternator was overcharging (charging at around 15. 5 ish) if the battery is fully charged or if the alternator pulley doesn't allow full output at idle. If you don't do this, some of the wires that run to the back of the alternator can short out if they touch the car body or engine. An experienced mechanic will be able to tell if a car has bad alternator bearings just by listening to the alternator. I measured the battery voltage when the car was off and it re. Here are some common causes of trouble and techniques to help you and your technician find and fix problems: Alternator — Loose wiring can make your alternator appear defective. Fixing electrical problems is a skill that every car owner must possess. Here's what to do. Generator Testing. Learn how to test it, how to replace it, and where to find the best deal on a new one. The crankshaft is the first component involved in starting an engine, and like the engine itself, a problem with the crankshaft will bring your whole car to a literal standstill. How to identify your GM Internally Regulated Alternator Delco Remy (System Integrated) SI alternator were used on GM vehicles between 1969-1988. Some of the things to look for are no-starting and trouble starting, dimming lights and problems with stereo system output. A few telltale signs are dim headlights, poor stereo system performance, or an alternator that simply wears out quickly. This is because the alternator is failing to recharge the battery, meaning it uses up its capacity. Take the car to your mechanic to have the alternator checked for proper operation. If the alternator is not working properly, the battery may be fine but a new alternator may be in order. It could be my computer or pulleys in the wrong too so I can't risk buying a new one and still having the problem. You also need to load test the batteries, the proper way to load test is to first fully charge the batteries, then remove the surface charge by turning on the lights (high beam) for several minutes. Take it to a professional for a final diagnosis. This test can be performed by your dealer, auto mechanic or yourself. You should see something between 13 and 15 volts when running. Step 2: Loosen the two bolts that hold the alternator in place. The battery must have picked up a very decent charge in 20 minutes from the alternator. Without starting the car, you can check the battery gauge on the dashboard. The alternator uses the principle of electromagnetism to produce current. I measured the battery voltage when the car was off and it re. If the car gets off immediately when you remove the ground cable, it means the alternator and not the battery has to be replaced. It could be that your alternator is ok but your battery is bad and won't hold a charge. Is the alternator charging the battery, check the output of the alternator 3. If the battery checks out, it's time to look at the alternator. The alternator should also be checked for any faulty diodes. Watch your temperature gauge – don't allow the car to overheat. It is typically found in front of your car's engine, with a pulley attached to the crankshaft via an alternator belt. The primary functions of the battery are to start the vehicle and provide power when the vehicle is not running. Apply the wheel chocks - Place the wheel chocks around the driver side rear tire. When the alternator completely fails, your truck could start slowly or not start at all. One of the most common problems on an aging alternator arise from worn out brushes. The alternator is located at the front of your engine. I removed it from the vehicle and took it to Napa and they said it tests good. You can do a simple test to check your alternator's performance. A loose drive belt can cause an. NAPA Auto Parts - Buy Car & Truck Parts Online | Auto Supply Stores Near Me. And in the air compressor system the pressure regulator stops and starts the compressor as needed to maintain the proper level of pressure. So, you'll want to check for the below signs to determine if it's just the battery or. Test the alternator leads by connecting each in turn with the voltmeter to an earth. The car has had 5-6 repairs over the last 6 years. The DC voltage output will also be very low. If increasing the RPM of the engine slightly causes the alternator to exceed the requirements, then it may be necessary to use a higher rated alternator, raise the engine idle speed (if possible. alternator problems If this is your first visit, be sure to check out the FAQ by clicking the link above. Alternator Output Test. voltage drop, check connections at alternator and battery as well as for an use of undersized cable. A good way to tell if it's the alternator pulley specifically is to listen for whether or not your automobile wails even before you touch the steering wheel. The alternator recycles the power your car battery uses while driving, restoring the power it has lost while supplying the climate, engine management, entertainment and host of other systems with the power they need to run correctly. Car Battery or Alternator? Learn How to Tell The Difference. If the device reads 12 volts or less, the alternator has gone bad. Part 1 of 13 - How to Rebuild an alternator. EDIT: Because there has been so much conjecture and comments thrown in below this answer, I'm adding some stuff from what appears to be an authoritative web source. The last thing you want to have happen when you’re trying to figure out when to replace a car battery is to discover that you waited too long to replace the battery and you’re stranded with a car that won’t start. 2 volts) to effectively charge a 12 volt car battery. To see if this alternator test article covers your specific 3. Acura TSX: Why is My Battery Not Charging? If your charging system is not up to the task, you may have a hard time getting to your destination, if you can get your car started at all. When the smoke clears, that “simple test” could end up costing you several thousand dollars for new electronics. Download this document in PDF format for printing. The alternator takes the energy from the crankshaft and turns it into the electricity that is stored in the battery of your car. Hope this will solve the RPM issue. In order to check the alternators, ignite the car and remove the ground cable from the battery. Solution: Replace your failing alternator bearings , or replace the alternator itself. A bad alternator will not properly charge the battery. 3) Turn on Headlights to High Beam. When the engine spins the alternator around, the alternator induces an AC voltage that is converted to DC and used to charge the car's electrical system. Voltage regulators are commonly found in vehicles and other electronic equipment. Know the warning signs of a failing alternator and what to do if it goes out. How to check the alternator with multimeter. 1A Auto not only knows everything about car and truck alternators, but we stock the highest quality, best fitting aftermarket alternators available. The rotor, brushes, and other internal parts of an alternator wear out over time, so replacing it is something everyone eventually needs to do. To know if your car alternator is bad, first test the headlights. easy way to test if an alternator works. If the alternator is charging, you could send a voltage spike through the electronic equipment on the car and possibly cause all kinds of damage. If you go with a rebuilt alternator, make sure you go with a good brand name. Thanks to Wally Plumley who pointed out that:-This test will not detect intermittents due to vibration/temperature-This tests the alternator/voltage regulator combo as a unit. Alternator replacement can be done at a car dealership, an independent repair shop, or car-repair chains like Pep Boys or Sears. Read also: How to check a fuse in a car. The alternator is a key component in running the electrical systems in your car. Test C -Testing the actual output of the alternator is known as "Full Field Testing". I tried to pull it out, actually took the plastic off but still cannot get those stupid prongs out. These can include the power windows, power locks, dashboard lights, air conditioning, even your car radio. When you have tested the charging system of a car fitted with an alternator, and the checks in How to test a car battery point to a fault in the voltage regulator, make sure that you need to replace it. It was probably only 1-2 min. In this guide, we look at how much an alternator repair will cost and why it costs what it does. A Type-A circuit has the voltage regulator on the ground side of the field coil. Put the alternator in a vice. Volts are the capacity of a given electrical current, and amps are the current's power. This test can be performed by your dealer, auto mechanic or yourself. 5, it's a good bet the alternator is good. Get Discounts & Coupons. This will take you step-by-step on how to properly set up your device and how to run a few easy test to make sure that everything is running smooth in your vehicle. Is the alternator charging the battery, check the output of the alternator 3. If it's worn out, get it replaced. If you spot. The alternator takes the energy from the crankshaft and turns it into the electricity that is stored in the battery of your car. if it's 12 or less, the alternator isn't putting out anything. Then remove any remaining nuts from the alternator and it should slide right out. Using a funnel helps avoid spills. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. I hated to convert to an alternator system because I was trying to keep the car as original as possible. The least expensive multimeter will show this characteristic on a diode and a cheap digital multimeter will have a settin. By taking out more than you are putting in. The astonishing thing regarding "The Magic of creating Up" is just how often it defies common sense. Alternator Test A new alternator should give an output that's 20% more than the vehicle system requires and should have been set to this level during manufacture. How to Test Alternator with a Voltmeter Alternator test with a voltmeter. A dead car battery is the first sign that something might be wrong with the alternator. The light in the test jig should light briefly and then go out indicating that alternator is working and the exciter terminal (-) has come up to alternator output voltage. YourMechanic can also test your battery to find out if it’s the reason why your car won’t start. Or, if you are mechanically adept, try the following yourself: While the engine is running, use a multimeter to check the charge at the alternator output. Still it's charging the battery with it running. ) 5) Increase motor speed to about 1500 RPM. on the running vehicle. Testing a car alternator on the bench, might become tricky if you make the same mistake i did here ;( When i did this test the power source i used to rotate the alternator was not rotating fast. Because the alternator is connected to (and critical for) other vehicle systems, any mechanical auto problems can have an effect on its function and have an effect on diagnosing car problems. You might be asking how can I tell if the alternator pulley is clutched. Last month's article dealt with the principles of DC electricity and how your car's battery functions. 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. Alternator Output Test. Go to the drop-down menu bar at the lower left corner of the Waveform Library window and select Alternator AC ripple / Diode Test. Though there could also be many other problems related to the car battery like, having a bad alternator , but if there is a bad battery you can surely figure out this problem with some of the most important and crucial signs which are apparent when you start your car or try starting it. The jerk behind the counter will test your allegedly defective car battery for electrical performance with a battery tester. “Any unusual sounds need to be checked out,” says Christoph Erdel, service manager at highly rated Euro Motorworks in Indianapolis. If it’s in the range, it’s good. The alternator in the car WAS good before I installed it in my eclipse. A car's alternator is not designed to fully restore a depleted battery, but rather to maintain a healthy one. The alternator is what converts the spinning of the engine into power that goes back into your battery. To test your alternator, you'll need a voltage meter and amperage meter, or a multi-meter that reads both voltage and amperage. After the load test, recharge the battery as soon as possible. When the alternator is going bad, other systems that are powered by the alternator may start to act up. It seems the lighting controls seem to be a problem as the battery and alternator checked out fine. Restart testing from step 1. The DC voltage output will also be very low. The following symptoms should give you an idea of what's gone wrong, but if you're still not sure, you can always bring your vehicle to Advance Auto Parts for a charging and starting system test. Go back to the inside of the vehicle and eyeball the dome light. In this guide, we look at how much an alternator repair will cost and why it costs what it does. A short chirp noise during engine start-up or shut down is most likely caused by a worn overrunning alternator pulley. The astonishing thing regarding "The Magic of creating Up" is just how often it defies common sense. Find Your Owner Manuals. 200 Loans For People With Poor Credit. There is a simple way to check the alternator. If the brushes check OK, do this test:. You replaced it and then the new battery died too. when you start the engine or accelerate, the belt should not squeal or flap. This diagnostic will help you sort out any charging issues you may have. Theses are the measurements you requested: Car running under load-12V, Alternator to battery ground - 13V, Battery positive to block ground 11V, Battery positive alternator body 12. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. A common but dangerous way to test an alternator THIS IS COMMON, BUT DANGEROUS !!! DON'T DO IT!!! The old "backwoods" way to test an alternator was to start the car, then disconnect one of the battery terminals and see if the car keeps running. It seems that when I replaced the alternator choke I did not disconnect the battery and by unhooking it and hooking it back up it shorted the alternator internally. Warnings lights in your car instrument panel signal that something is wrong within your vehicle. Replacing the belt is an easy and cheap fix. Allow the engine to idle for around five minutes. When the smoke clears, that "simple test" could end up costing you several thousand dollars for new electronics. ThereÂs more to checking a battery than testing the voltage and looking inside for low water. *** The Battery voltage Should read between about 13. Without starting the car, you can check the battery gauge on the dashboard. Alternators need repairing like any other car part during a car's life span and it is a part that will definitely need repairing as it is essential to the smooth running of a vehicle. Tools needed: Multimeter. After the battery is full again the alternator's task is simply to supply the normally smaller amount of electricity needed to run the ignition, lights, radio, etc. Shop online for original OEM & replacement parts. I just had to repalce the alternator on my rig and the parts guy was lost on what one it was suppose to have as there were two listings, fortunately buy comparing the the two on the bench it was determined to be of course the more expensive one as the electrical connections were slightly different and the clocking was a 180 degrees different. 2 is optimum). The Alternator. How to test car battery for dead cells. Carry out the Load Test and No-Load Test. In this guide, we look at how much an alternator repair will cost and why it costs what it does. Log Into FordPass. Read more. Using an automotive alternator to construct a wind-powered electrical generator can reduce or eliminate dependency on "grid" power, even if the wind turbine is only used for How to Build a Wind Generator with a Car Alternator | Hunker. Dimming Lights The alternator by itself can be the cause of dimming lights, fading radio, and/or stalling. Check the negative side for the charging circuit the same as the positive with your meter's negative lead on the alternator case, or ground strap if equipped, and the positive lead on the batttery negative post. An automobile alternator is essentially an AC generator. Simply connect the ammeter in series with the battery’s ground terminal (with the. If the alternator is going bad, you will notice that dashboard lights appear dimmer than usual. The crankshaft is the first component involved in starting an engine, and like the engine itself, a problem with the crankshaft will bring your whole car to a literal standstill. check the belt for wear or damage like cracks, glazing or contamination. If you hear a short buzzing sound (1 to 5 seconds), the pulley’s bearing may have worn out and the overrunning alternator pulley may require replacement. But first, why would your alternator fail? Most aircraft alternators are powered by a drive belt that's connected to your engine's crank shaft. Often old or worn out alternators ground themselves internally causing a short. You can also take your alternator, starter or battery into our store and we'll test it. I decide to take the battery to O'reilly and have them check it out, thinking it might have a bad cell, it checked out ok, so during some reading on the net that I did they said an alternator for a 2003 Escalade which is a 145amp alternator would bolt right into my car, so I picked one up, went home took the Mechman out and installed that one. With all your gadgets ( accessories ) turned off that alternator should be able to keep the engine running even without a battery in the car - that was the true alternator test back then. How to Test a Voltage Regulator. How to Check an Alternator - Using a Voltmeter Buy a voltmeter. I made a post a while back about putting my battery in the wrong way (at night, half asleep). Minis built up to 1969 (i. Procedures for the regulator bypass test is similar to the charging system output test, except that the regulator be taken out of the circuit. To confirm if this component is indeed the culprit, you can check it with an ohm meter , voltmeter, or multimeter. Car Battery or Alternator? Learn How to Tell The Difference. Dimming Lights The alternator by itself can be the cause of dimming lights, fading radio, and/or stalling. Your car’s battery is charged as your driving along by the vehicle’s alternator, but if there’s a problem with the alternator or you’ve run the battery down too far to start the vehicle, then a quick charge with some jumper cables should get you moving again. Testing to see if the alternator is BAD or not, on your Ford (or Lincoln or Mercury) 4. In older cars (before about 1964) this was done with a generator. So, you'll want to check for the below signs to determine if it's just the battery or. When diagnosing battery trouble, you must check the alternator to see if it is charging correctly. If you can't safely get to the alternator you can test at the batteries, but it's not as accurate. Also, if the battery itself is bad, an alternator in working order won't be able to charge it. No Probs, to make it easier, just test the output at the battery, not sure on the specs of your alternator, but it should put out close to 13. Said in a different way, if your alternator pulley is 3" in diameter your engine pulley should be at least 6' in diameter. If your battery is good, and your alternator isn’t working, the battery will still lose its charge because the alternator isn’t keeping it charged. Temporarily disable the ignition in your car (for example, by removing the fuel pump fuse) and turn the engine over with the starter motor for 15 seconds. It is typically found in front of your car’s engine, with a pulley attached to the crankshaft via an alternator belt. Then test after an overnight rest. This is most likely due to a dead battery or a failure in the charging system. on the running vehicle. Get your car fixed Make Acura Audi BMW Buick Cadillac Chevrolet Chrysler Dodge FIAT Ford Geo GMC Honda Hummer Hyundai Infiniti Isuzu Jaguar Jeep Kia Land Rover Lexus Lincoln Mazda Mercedes-Benz Mercury Mini Mitsubishi Nissan Oldsmobile Plymouth Pontiac Porsche Ram Saab Saturn Scion Smart Subaru Suzuki Toyota Volkswagen Volvo. Connect the meter leads to the battery terminals and look for 13. Battery life is defined as the period of time in which a battery is capable of being recharged and retains the charge applied. But, let's face it. 3 batteries and 2 alternators. If you don't have enough volts, it could cause serious and permanent damage to your car. A man came out to try to get the car going, but he was absolutely baffled and could not fix it, but did establish that there was nothing wrong with the battery or alternator. you will need to check output also with lights on an if it drops in voltage you probably have a bad alternator,most auto parts stores can test. Alternator replacement can be done at a car dealership, an independent repair shop, or car-repair chains like Pep Boys or Sears. A car's alternator is not designed to fully restore a depleted battery, but rather to maintain a healthy one. Most commonly, technicians perform the starter and alternator replacement by removing the old hardware and parts using a socket set and other hand tools. Then remove any remaining nuts from the alternator and it should slide right out. To find what amperage your alternator is, you must first understand the relationship between volts and amps. Although this does work, it's not recommended. The alternator is a compact generator primarily consisted of a magnetic coil and a metal rod. How can a car alternator be tested with out being removed from the car? I want to test my car alternator but i aint really looking to remove it from the car. Car Battery or Alternator: How to Tell Where the Problem Lies January 27, 2012 Almost all of us have experienced the problem where either your car battery or alternator just conks out, and you can't make out which one to replace. Although knowing how to test a car battery is an important skill, when dealing with a seemingly dead battery, the problem might simply be in the terminals. Any simple diode will exhibit a 'front-to-back' ratio since they are designed to allow current to flow in only one direction. Thanks to Wally Plumley who pointed out that:-This test will not detect intermittents due to vibration/temperature-This tests the alternator/voltage regulator combo as a unit.