Other Possible Causes Failed Alternator Voltage Reading

Dan Ferrell writes about do-it-yourself car maintenance and repair. He has certifications in automation and control technology.

The alternator is at the middle of the charging system of your vehicle.

Photo courtesy of Pentti Immonen on Wikimedia

Alternator bug and charging system issues tin can touch on your vehicle in different ways. You may observe:

• your ALT or CHARGE indicator calorie-free comes on,
• your engine is hard to outset and cranks slowly, or doesn't creepo,
• your battery demands lots of water,
• your alternator makes noises,
• or your headlights of a sudden become dim.

These and other problems may exist caused past a mistake in the charging system.

Before you kickoff replacing components with the promise of fixing the problem, y'all need to determine which component or components are causing yous trouble. Often, it is possible to diagnose and solve the problem on your own using a few uncomplicated tests and tools.

The sooner you find out what is causing trouble, the improve. Y'all'll forestall a faulty component from ruining other parts in the system, which would make your repair more expensive.

This convenient troubleshooting guide volition aid you lot find out what you need to know, using a few simple checks yous can do at home using a exam light or digital multimeter (DMM) and possibly a few other common tools.

It is a good thought to have on hand the vehicle repair manual (or a skillful aftermarket manual) for your detail car make and model. It will help y'all identify wires, specific components, and possibly propose some specific tests recommended past your manufacturer.

If you want to test the condition of the system equally a diagnostic starting point, do the tests described in the post-obit section, "Full general Charging System Check."

However, if yous need help for a specific problem with your charging system—for example, an over-charge or under-charge status, discharging bombardment, or noisy organization—then skip over to the "Charging System Problems and Potential Causes" section.

Index
I. Common Symptoms of a Bad Alternator or Charging Organisation
II. General Charging Organization Checks
Three. Charging System Problems and Potential Causes
4. Troubleshooting for Unusual Voltage Organisation Drops

The battery indicator should turn off when your engine is running.

Photo courtesy of Kskhh on Wikipedia

I. Common Symptoms of a Bad Alternator or Charging System

Indicator Light On

Usually, the offset sign that your charging organisation is in trouble is a "bombardment," "ALT," or "Charge" warning light illuminating on your musical instrument console while driving. It means that the alternator voltage output is beneath 12 volts, or over its limit or has stopped charging the bombardment and your machine is running on bombardment ability.

If the low-cal illuminates only intermittently, it normally indicates a loose or worn drive belt or serpentine belt, worn-out or bad carbon brushes in the alternator. But remember that the light doesn't ever mean in that location is a bad part; the light may be triggered by a sensor giving a incorrect bulletin or there'south something wrong with the excursion itself.

Read More from AxleAddict

Engine Cranks Slowly, Doesn't Crank or Stalls

When the battery is undercharged, you may accept difficulty starting the vehicle, the engine cranks slowly or doesn't creepo at all. Also, the engine may stall if the alternator tin't produce enough power to run the ignition system. Get over the next section on "General Charging System Checks," and, if necessary, check the section "Four. Troubleshooting for Unusual Charging System Voltage Drops." further down in this article.

Bombardment Overheating and Using Too Much Water

An overcharged battery causes the battery to overheat. You find yourself adding water to the battery often. If the trouble is non taken care of on time, it can ruin your bombardment. Besides going through the side by side section, make sure to bank check section Four below on "Troubleshooting for Unusual Charging System Voltage Drops"

Noises Under the Hood

Squealing, buzzing or grinding noises coming from the engine may be acquired by bad alternator components, a loose or worn-out serpentine belt, or a faulty belt tensioner, loose alternator pulley or mounting bolts, worn bearings, or faulty diodes. See the "Checking for Alternator Noises" subsection further down in this commodity.

Dimming Lights

If you notice the headlights, instrument panel, or interior lights dimming or flickering, power windows running slow, radio or gauges don't operate as they should, either your battery has a low charge, or there's ane or more than faulty diodes inside the alternator. Cheque your battery and see the "Alternator AC Voltage Leak Cheque" subsection further down in this article.

Check the drive belt for aligning and tensioner for proper operation.

Photo courtesy of Una Smith on Wikimedia

Two. Six Tests for the Charging System in General

These series of charging system checks help diagnose the general condition of your charging system. They can aid you confirm that you actually have a problem in your charging system and locate the source of the problem.

1. Brand a Visual Inspection of the System

With the engine off, popular the hood open and visually inspect the different components of the charging system. Look for a worn out or loose drive belt, alternator connection problems, loose alternator mounting bolts, and corrosion and dirt effectually the battery example and cables.

When inspecting the drive belt, check for adjustment. If necessary, suit the belt with the help of your automobile owner's manual or repair transmission. Inspect the belt for signs of cracks, cuts, shiny spots, deterioration or other signs of habiliment or damage. Alter the belt and belt tensioner at the manufacturer's recommended interval.

2. Bank check for Wiring Issues

Inspect the wires and connections at the back of the alternator, at the remote voltage regulator (if applicable), and at the battery. Look for corrosion at the connectors, damaged wires, and burned and missing insulation that might suggest an electrical short.

3. Practise This If the Indicator Low-cal Stays On, or Goes On and Off

Follow the next steps:

• Start the engine and use the emergency brakes. Prepare the transmission to Neutral (manual) or Park (automated).
• Connect a voltmeter across the battery terminals.
• While watching the voltmeter display, start wiggling wires at the back of the alternator, the battery, and the remote voltage regulator (if there is one).
• If the voltage reading on the meter display goes upwardly while wiggling ane of the wires, you've found a bad electrical wire or connection.

Instead of using a voltmeter, you can have an banana watch the indicator light on the instrument panel to see if information technology turns off every bit you jerk various wires and connectors. Once the lite turns off, yous've constitute the trouble connector or wire.

4. Check for Alternator Noises

Bad alternator bearings, rectifiers, rotor shaft, stator winding, sideslip rings, brushes and other parts inside the alternator with mechanical or electrical issues can become noisy.

Hither'due south a test you can do: Use a length of vacuum hose to listen for alternator noises. The hose will amplify the noise if information technology's coming from the alternator. Merely be very careful around moving parts while you do this test.

• Start the engine.
• Identify 1 end of the hose against your ear and motility the other end around different points of the alternator trunk.
• Listen for whining noises (this tin bespeak a bad diode or an over-charging condition), grinding (bad bearing), squealing, or other abnormal noise. If necessary, accept your alternator checked.

5. Check for Nether-Charging and Over-Charging

The adjacent 3 tests are best washed using a load tester, simply you still can use your digital voltmeter. You practise this by measuring system voltage while loading the organization.

5a. Showtime, measure battery base voltage to make sure you have a fully charged battery.

• Turn on the high beams for 10 seconds and so turn them off.
• Wait for two minutes
• Measure battery voltage across the battery posts with your DMM. Y'all should go betwixt 12.four and 12.6V. This ways your battery is fully charged. If you get a reading below 12.4V, charge the battery before continuing.

5b. Measure the Charging System'south No-Load Voltage

• Ask an assistant to start the engine and concur engine speed at almost 1500 RPM.
• Measure voltage across the battery with your DMM. Y'all should go 0.5 to ii volts higher than base voltage. If y'all are getting more than 2 volts above base voltage, most likely your alternator is over-charging the battery or the bombardment is faulty. Other potential problems are a faulty voltage regulator or a problem in the charging system wiring. As office of your wiring checks, encounter the department "Troubleshooting for Unusual Charging Arrangement Voltage Drops" below.

5c. Measure charging organisation load voltage with a loftier-current-condition organisation measurement.

• Ask an assistant to start the engine and hold engine speed at about 2000 RPM. Turn on all electrical accessories like A/C, blower motor, headlights, defroster, wipers. But don't turn on the heated windshield if your vehicle has one; alternator voltage may increase to over 100V and this can be unsafe.
• Accept a voltage reading across the battery posts. Your reading should be at least 0.five volts in a higher place base voltage for your system to keep up with electrical organisation demands. Otherwise, the charging system can't run into the demand and charge your battery. This error could point to a faulty alternator or voltage regulator. Check the department "Troubleshooting for Unusual Charging System Voltage Drops" below to check for wiring issues that can pb to this condition.
• NOTE: These measurements correspond to an ambient temperature of most 70º F. The charging voltage volition increase as temperature drops, and charging voltage will subtract equally temperature goes up. So keep this in mind when making your measurements.

6. Bank check for Alternator Air-conditioning Voltage Leak

Alternators apply diodes to rectify alternating electric current produced past the alternator into direct electric current. When i or more than diodes become bad or a stator winding fails, the alternator can cause all kinds of bug. Ac voltage leak can cause your lights to dim and drain power from your bombardment, for example. Usually, you tin can detect this leak past measuring AC voltage at the alternator.

• Commencement and let the engine idle.
• Set the parking brake and your transmission to Park (automated) or Neutral (manual).
• Gear up your meter to a low AC voltage range.
• Ask an assistant to increment engine RPM to 2000 rpm.
• Touch on the red meter lead to the alternator bombardment terminal B+.
• Touch the black meter lead to the alternator instance (ground).
• If your DMM reads 0.4 Air conditioning volts or less, the diodes are good.
• If your DMM reads 0.5 AC volts or more, the diodes or stator is faulty.

Once y'all've adamant the condition of the organization, you can go over the next department to nix in on the potential problem(s) that may exist causing the status of the charging arrangement.

A single bad battery cell can prevent your charging organization from working properly.

Photo in the public domain.

3. Charging System Problems and Potential Causes

To speed up your diagnosis and repair, wait upwards the arrangement status that most resembles your problem and go over the potential causes described nether that condition. Some checks or tests may be suggested as appropriate.

1. If the Battery Seems to Stay Undercharged

You accept already charged your battery a couple of times and yous merely found out the battery is undercharged again. Before you arraign your bombardment, or the alternator, here are some preliminary checks you lot may want to practise.

a) Check the drive belt or serpentine belt, especially if you haven't replaced information technology in the concluding five years. Brand sure the chugalug has the proper tension. Look for signs of wear or harm like cuts, shiny spots, missing chunks. Today serpentine belts don't show signs of wear, even if they need to be replaced. Use a belt article of clothing indicator or bank check your maintenance schedule for the replacement interval suggested past your automobile manufacturer. Yous may find the schedule in your automobile owner'southward manual or your repair manual.

b) Along with the bulldoze chugalug, check the belt tensioner as well. Brand sure it turns freely and is noise-gratuitous. Car manufacturers recommend replacing the tensioner at the same time y'all replace the drive belt.

c) Brand sure your battery connections are tight and make clean. However, just considering the terminals look clean, information technology doesn't mean they are tight and in skilful condition. Look for damage to the cable and the terminal itself that may foreclose proper electrical electric current menses.

d) Check your bombardment yourself, or take it to your local auto parts shop. Many of these stores will examination your battery for free.

east) There's a parasitic battery bleed stealing power from your bombardment.

• A quick test is to connect a test light in series betwixt the positive battery cable and the positive battery post. If the test lite comes on, there is an electric drain in ane of the systems.
• Kickoff, unplug the alternator electrical connector. If the examination calorie-free goes out, the alternator is causing the drain. If not, locate the parasitic drain.

f) Don't overlook the starter motor: a failing starter motor may draw excessive current during functioning, draining battery power. If necessary, have your starter motor or starting organization tested.

chiliad) If you recently added an electrical accessory to the vehicle, yous may have over passed your alternator's capacity.

h) There could exist an alternator wiring problem.

i) Accept the alternator and battery checked.

2. If the Arrangement Seems to Be Over-Charging

Besides exam results, another potential sign that your bombardment is being overcharged is that your battery terminals proceed accumulating corrosion.

Here are some checks you lot want to do:

• Make sure that all the connections to the alternator, remote voltage regulator (if applicable) and battery are make clean, tight and in good status.
• Cheque your battery or take it tested at your local machine parts store. A bad bombardment jail cell can cause the alternator to over-charge the practiced battery cells.
• Bank check for a bad alternator voltage regulator and circuit. Consult your vehicle repair transmission, if necessary.
• Make sure yous have good footing connections at the alternator (alternator case) and voltage regulator, peculiarly if your vehicle uses a remote voltage regulator. Grounds should be costless of rust, and the alternator and remote voltage regulator mounting bolts should be clean and tight.
• Check the alternator rectifier or have your alternator checked at the motorcar parts shop.
• Also, carry the tests described in the Troubleshooting for Unusual Charging Organization Voltage Drops beneath.

iii. If the Alternator Is Not Charging the Battery

When your tests point to an under-charge or no-charging condition:

• Brand sure the drive chugalug is not loose or worn out.
• If necessary, borrow a practiced battery just to operate the engine and confirm that your drive chugalug and belt tensioner are operating properly.
• Manually bank check the belt tensioner for proper operation. Brand certain the tensioner pulley turns freely and without noise. Bank check it for damage.
• Manually plow the alternator caster and make sure information technology turns without a trouble. If one of the bearings has seized, information technology won't allow the alternator to plough freely.
• Check that the connections at the battery, alternator, and remote voltage regulator are clean and tight.
• Check for a diddled fuse or fusible link. Consult your vehicle repair manual, if necessary, to locate the alternator fuse or fusible link.
• Do the tests described in the department "Troubleshooting for Unusual Charging Organisation Voltage Drops" below.

4. If the Engine Makes Noises

Noise can be a sign of alternator problems when it comes from the charging system. The next checkpoints will help y'all isolate the source of the noise.

• Check the drive belt or serpentine chugalug. Wait for signs of article of clothing or damage like cuts, shiny spots or missing chunks nether the belt. A worn out belt can bleat during performance.
• Also, check the belt tensioner for proper operation and damage. It should rotate freely.
• Make certain the alternator is properly mounted. Loose mounting bolts can cause the alternator drive chugalug and bulldoze pulley to become misaligned and noisy.
• Check the alternator for noises. Run into the General Charging Organization Checks section for a simple procedure for this.

v. If Lights Dim During Engine Performance

Most alternators use diodes inside a rectifier to turn Alternating Current (AC) into Direct Current (DC) for use by the arrangement. When one or more diodes get bad, Air-conditioning tin can leak into the electrical arrangement. Sometimes you can notice this when the headlights, instrument console lights, and other interior lights dim during engine operation. To examination your alternator for Air-conditioning current leaks, see the Alternator AC Voltage Leak Check subsection in the previous department.

Measure system voltage and drop voltages using a digital multimeter.

Photo courtesy of Steve C on Wikimedia

Iv. Troubleshooting for Unusual Charging System Voltage Drops

A charging arrangement voltage drib check can help y'all locate the source of an under-charge or over-accuse status due to problems in the wiring or connections betwixt the battery and alternator.

ane. Start the engine and let it idle. Utilize the parking brake and set the transmission to Neutral (manual transmission) or Park (automatic transmission).

ii. Turn on the high beams to provide a system load. And take an assistant raise engine speed to most 1500 RPM. If your vehicle is equipped with a heated windshield, don't turn it on; this tin can make alternator voltage go over 100 V. Since you'll exist working around alternator connections, this could be unsafe.

3. With your voltmeter exam leads, touch the positive battery mail service and the B+ final connector at the back of the alternator.

4. Check your meter display. You should get around 0.4V or less of voltage drib. If your voltage drop is higher, it tin atomic number 82 to an under-charge condition. Cheque the connections in that part of the circuit for a loose wire, corrosion at the connectors or wiring damage that may prevent proper current flow between the battery and alternator. Also, check the electrical connections at the back of the alternator and at the voltage regulator.

5. At present repeat the test, merely this time, connect your meter leads between the battery negative post and the alternator instance.

six. Check your meter display. Again, yous should go a voltage reading around 0.2V or less. If your voltage drop is higher, there's something wrong. This can lead to an over-charging condition. Checking that part of the circuit, make sure the bombardment ground connection is good, make clean and tight. Add a temporary ground connection from the battery to the chassis. If this removes the loftier voltage drop, check the engine to torso grounds connections. They should be clean, tight and in adept status.

Watch the next video for a visual reference on voltage drop checks.

Alternator problems are not uncommon later on a few years of operation. A typical alternator may final anywhere from eight to 12 years. So don't be surprised to find your alternator going bad or the system developing problems after a few years of trouble-free operation, even if you have maintained your car well.

The key betoken here is to do the proper diagnostic as soon as possible because a bad alternator can ruin an otherwise good bombardment, and other components too, depending on the fault.

Once you decide that your alternator is bad, you lot have several options. You can replace it with an original 1 from your dealer, an aftermarket replacement, or a rebuilt unit. Aftermarket alternators are a good option and less expensive, and many of them are only equally good every bit their OEM counterparts. And rebuilt alternators are not as bad either. So consider your options.

This content is accurate and true to the best of the author's knowledge and is not meant to substitute for formal and individualized advice from a qualified professional person.

Questions & Answers

Question: I have a 2000 Monte Carlo and my battery light is notwithstanding coming on after changing my starter and battery and alternator. Mmy car will close off after 2 to three minutes. What could be the problem?

Answer: The trouble could be in the charging excursion. This other mail may help:

https://axleaddict.com/auto-repair/Charging-System...

Question: I got a 2012 Nissan Xterra. I just installed a new alternator and new battery. It starts up good and idles good now as well, simply when I give it total throttle and get close to 3,000 RPMs, my battery light and park brake lights comes on and flashes at me. And the bombardment volt guess goes down a whole lot. What could be the trouble?

Answer: Check the alternator belt and tensioner. Belt should have the proper pressure. If it's loose, it won't charge properly during difficult accelerations. Check voltage at the battery when accelerating (at idle and emergency brakes applied). You should become effectually 13.v or so. Otherwise, there could be a problem with the voltage regulator. Y'all may need to supplant the alternator. If not, cheque the wires and connections between the battery and alternator.

Question: I've got a 1982 Chevy K10 half-dozen.2L and I swapped the alternator. It's charging but it'south charging slowly. It'due south running at 12.fourscore volts constantly. I'yard out of ideas?

Answer: Check the connections. A loose, corroded or damaged wire or connection can cause this type of problems:

https://axleaddict.com/auto-repair/Charging-Arrangement...

If the alternator was working fine in the other vehicle, take the battery tested if necessary.

Question: I apply a Golf 4 alternator on a Golf 4 as I saw fit. It runs fine, and in that location aren't whatsoever alarming audio. The problem is that it doesn't charge when I offset the car. I take to rev the engine hard, and and so it starts to accuse normally. What the problem?

Answer: If the warning light is coming on when you lot rev the engine, cheque the light excursion. specifically, you should check the resistors in the gauge cluster.

Bank check the drive belt starting time for tension and vesture. Also, make sure that the back wires are properly connected and clean. Then, bank check the voltage regulator.

Question: Why is the alternator overheating even though the engine is off?

Answer: Check your battery and circuit between the bombardment and alternator. Also, check if there are any modifications to the system?

Question: Battery tested fine, but alternator voltage would go upward and down. Occasionally, a BATTERY Arrangement FAILURE light will come on. Could it exist a sensor/fuse problem since it doesn't stay on all the time?

Answer: The alternator could be faulty. Simply y'all may want to run a voltage drop examination on the circuit first. Some models, like GM, have a fusible link in the excursion. Make sure that it's good. This other post has a voltage drop section that may help:

https://hubpages.com/auto-repair/Charging-Organisation-C...

Question: When my engine is at idle the voltage is around 13V, simply when I turn on the headlights and Air conditioning, it drops to 11V to 11.8V. What seems to be the problem?

Answer: My guess is the AC pulley may be putting a strain on the crankshaft pulley, affecting alternator output. Or the Air-conditioning pulley is affecting the belt. Bank check how the iii operate when the Air-conditioning is on.

Question: I take an 04 Lincoln aviator. I changed the battery, alternator and I am still getting a check charging system bulletin. What practice I do next?

Answer: Make certain you actually have a charging trouble. Your local auto parts shop can cheque the alternator and battery for you. If in that location'south a problem, it could be in the circuit. If not, the circuit for the warning light might be the issue.

Question: I have a 2006 Toyota Yaris T3 998cc plate. My wife went to start it. It wouldn't start. It tried but was like the battery was apartment. I wiggled the wires going to the alternator and it struck up hands. Do these symptoms mean the alternator is no proficient?

Answer: Check first the wires for a loose or dirty connection; frayed wires, etc.. Checking voltage drib on the connections and wires tin can help a lot to locate faulty connectors and wires. This other post may aid.

https://axleaddict.com/machine-repair/Automotive-Volt...

Question: I accept a 06 Mustang GT. I replaced the alternator because information technology was causing a camshaft position sensor lawmaking. Subsequently replacing information technology and checking my work, the battery light with a warning "check charging organization" comes on. It comes on for a minute or and so then goes out for a few minutes. The battery seems to stay around 13.7 volts what could be causing the light to come on randomly? I have non driven it even so.

Reply: Cheque the excursion connections. This could be a loose or bad wire/connector. You lot may want to try a voltage drop examination. This mail gives you an thought of the test:

https://hubpages.com/automobile-repair/Automotive-Voltag...

Question: I accept a 2001 Toyota Solara with 158,000 miles. I've gone through 5 alternators in virtually 6 yrs. Even the Toyota oem. 2 reliable mechanics can't figure it out. I'm taking information technology to a store that specializes in electrical issues. Do you accept whatever ideas?

Answer: Knowing how the previous alternators failed can give a clue about the type of result you are dealing with (electrical, mechanical). Unremarkably when alternators failed prematurely is because of a bad battery (electrical), voltage regulator bug, loftier electrical loads (due east.1000. running Air conditioning fan at loftier) or a drive chugalug that is putting unusual stress on the alternator pulley (mechanical)(brand sure the belt is not too tight). Alternator quality tin be another gene of course.

Check for signs of fluid leakage around the alternator that might touch the stator or rotor or both.

Question: I have a good alternator, just my battery runs downwardly. It passed tests performed at two car parts stores. When this trouble occurred, I was able to get abode by starting the vehicle (2000 GMC Yukon, v.3L) by disconnecting the bombardment. Voltage when up shut to 14 co-ordinate to the judge. When I reconnected the batter at home, it was still dead. Got a new battery and have the same problem with battery drain. Exercise you take whatever ideas?

Answer: If you take some ability amplifier, or some other power accessories, this could be running downward the bombardment if the alternator can't keep upward with the need. Other than that, you may want to have the alternator checked in a shop, and run into where the charge is going while the engine is running.

You can check for a parasitic bleed that you lot may non be enlightened of. This mail can help you:

https://axleaddict.com/auto-repair/car-batterydrai...

Question: I installed a new 105-amp alternator in my 1982 Chevrolet C10. When I first the engine, it indicates 14.half dozen volts on the voltmeter connected to the battery. When I start the AC fan and the AC compressor, the voltage increases to xv.8 volts. After a while, the alternator stops charging; I remember it might be defective. I changed 2 alternators, but I still have the same trouble. What practise you think?

Reply: Check the voltage regulator and the battery. An automobile parts shop may check the battery for you. Also, may certain the circuit connections for the charging system are clean and tight and bank check the engine body grounds.

Question: I have a 2004 Taurus, and I've changed the bombardment and alternator but the charging system light is notwithstanding on. Any ideas why?

Respond: Cheque the fusible link, you can exam it with your multimeter.

Question: I have a 2005 Ford Taurus i mean solar day information technology wouldn't showtime. It finally started and flashing lights to cheque the brake system in the charging organisation, but then it wouldn't outset in one case it was jumped. It kept stalling, so nosotros had it checked at an automobile parts store. They agreed alternator replaced the alternator and information technology is still doing the aforementioned matter do you lot accept whatsoever idea what else could be wrong?

Reply: Check all the grounds -- battery to body and body to engine. They should be clean and tight. Bad grounds tin eventually, damage the alternator. Test for voltage drop on the grounds, battery and charging system.

Question: I had my alternator rebuilt. Now I am having a problem getting it to accuse at idle, I get 14.5 volts at 1500 rpm, simply as presently every bit I release the throttle it drops down to battery voltage, I've returned the alternator once already. He checked it again, replaced the regulator and said it's putting out full voltage, just on the car, it's doing exactly as I mentioned before, no voltage at idle, full voltage when revving the engine. Could this be a PCM outcome?

Answer: Check the belt and belt tensioner for the right tension. Take a expect at the connections at the dorsum of the alternator, especially the B+ connector. On early models the indicator light on the dashboard should come up on when the ignition key is in the On position, otherwise, you'll have problems at idle. In that location could also exist a problem in the charging circuit, a loose, corroded or damaged wire tin can also prevent full voltage at depression rpm. Take a look at the grounds and the output wiring to the battery. You may demand the diagram for this. These other posts may help:

https://axleaddict.com/auto-repair/Automotive-Volt...

https://axleaddict.com/automobile-repair/Charging-System...

Question: Our engine will take too much time to beginning. How can I cheque the alternator?

Answer: The problem might be with the bombardment, starting system, ignition or fuel arrangement. Check the batter status, cheque for spark and fuel pressure.

Question: I have a Toyota Corolla VVTI model 2004, I have changed the alternator merely the battery indicator is still present. I take checked the fuses and connections, but the problem continues. What could exist the upshot?

Respond: Have the battery tested, and check the connections in the charging system. Make sure they're clean and tight. Also, the check the engine grounds.

Question: My voltage is fine when I outset the vehicle, just after driving around for nearly 10-15 minutes, my voltage goes from 14v to xv.5-16v. I take an aftermarket voltage regulator, and a high output 320 amp alternator and my battery dies if I don't unhook the wire from my bombardment to the cars fuse box. Do you accept any ideas?

Respond: Yous demand to brand sure the alternator is suited for your awarding. These alternators need the right caster ratio and pulley diameter to work correctly. Also check that it has the correct size battery cables hook to the battery.

Question: I put my OBDll reader on my car and it says my charging system output is high. What does that mean exactly?

Answer: This basically means the alternator is overcharging the battery. Usually the problem here is the voltage regulator. Before replacing the alternator, y'all can take the alternator to a local auto parts store and have them check it for you. Make certain the alternator is the problem.

Question: What are the most mutual faults probable to occur in a charging arrangement? More than than half dozen points at least.

Answer: In that location tin can exist a problem with the circuit, voltage regulator, ignition switch, corroded battery cables, faulty bombardment, worn or loose drive belt, bad car figurer.

Question: I have a 2014 Nissan Pathfinder. I changed my alternator in July 2018. Alternator stopped working again on ii/half-dozen/2019 and replaced it on ii/7/2019. Back in the shop on two/11/2019 with bad alternator again. This time the alternator is overcharging. The alternators were bought from O'Reilly'southward auto parts. But found out they are rebuilt alternators, and non new. Nevertheless, the price was $400 for the role. Could in that location exist something causing the role to go bad and then quick or could it just happen to exist bad parts?

Answer: Brand sure you are using the correct battery for your application. On some newer models using the incorrect battery tin can affect the alternator, especially those that interact with the ECU. Also, bank check the belt and pulleys. Brand sure the pulleys are correctly aligned, and the alternator is properly mounted without rust accumulation, peculiarly the footing connections, including engine and battery grounds. Also, cheque the wiring for signs of electric faults. And yes, some models are very sensitive to using parts other than OEM, but starting time, make the previous checks.

Question: I have a 1998 Ford Mustang. I've changed the bombardment and the alternator. I'1000 still losing voltage from the alternator to the battery. It is just running on the battery. What can crusade this problem?

Answer: Y'all might want to brand a voltage drop test on the charging circuit. In that location could be a bad connection or wire that is not too evident. This other mail will requite you an idea on how to go about the test:

https://axleaddict.com/machine-repair/Automotive-Volt...

Question: I replaced the original alternator on my 2015 Kia Forte. The replacement alternator shows that it went bad and that I replaced it with the second one, at present it went downwardly. What is the problem? I accept too noticed the positive battery postal service on my battery gets hot. Exercise y'all take any idea what it could exist?

Answer: There could exist too much resistance on that side of the circuit. Check the cable for damage, or a problem at the connectors. If everything seems okay, take your bombardment tested.

Question: I have a 2003 VW Eurovan. Recently, the ABS lite went on, so, after a few minutes the regular reddish brake light lit and the car stopped. What is going on?

Answer: You lot need to download the trouble codes. There could exist a number of things that triggered the ABS light - issues with the tone ring, bicycle bearing, speed sensor (and wiring).

Question: I have a GM 3500 vi.0 with an overcharging problem. I ran new wires to the PCM and fuse box for the connector. I take a brand new alternator, PCM, and ACDelco battery. The power wire for the alternator to the battery reads correctly besides. But it is all the same charging to 15.6-16.0. What could peradventure be going wrong with my machine's alternator?

Answer: The problem could be on the ground side of the circuit. Increased resistance (loose, corroded grounds) can cause this type of trouble. Of course, you want to make sure you got the right alternator for your application. This other post may aid:

https://axleaddict.com/auto-repair/Charging-Arrangement...

Also, make sure to lookout man this other video:

https://www.youtube.com/lookout man?v=OqylgRKiC-A

Question: I have a 2012 Town and Country with 110k miles. Last year at effectually a 100k miles I replaced the alternator due to regulator failure. This twelvemonth I installed a new battery. The problem is the charging light comes on randomly. I drive around with a voltmeter to run these tests the moment it happens, only everything checks out. Why does the light come on and not go out?

Answer: Cheque the belt. A worn belt may sideslip intermittently, affecting the charging system. The problem with newer belts is they look practiced even if they are worn. Cheque the belt for tension and habiliment (use a chugalug habiliment gauge), tensioner, pulleys, and grounds, and especially engine grounds.

Question: I have an 03 Dakota. Information technology needed a new battery, however, the bombardment gauge goes to 0, and the idiot lite comes on afterward I drive it for a minute. Information technology starts fine and the lights are fine; but that gauge quits working. What causes that?

Answer: Bank check the alternator, perhaps a bad voltage regulator.

Make sure the drive belt is not loose or the idler bad, causing the belt to sideslip. If the battery accuse is not affected and everything else seems to work just fine, there could be a loose wire or connector in the circuit to the gauge.

Question: I take a 2007 Cadillac CTS. I replaced the bombardment, cranked up and the negative connectedness got hot. What would cause my Cadillac's battery to oestrus up?

Respond: If the negative cable gets likewise hot just cranking the engine, there's too much resistance in that part of the circuit. If this happened right afterwards installing the new battery, probably the negative cable is not well connected or is damaged or there's some corrosion. Y'all can likewise do a voltage drop examination on that part of the circuit. These posts may help:

https://axleaddict.com/auto-repair/How-to-Utilize-Volt...

https://axleaddict.com/machine-repair/Automotive-Volt...

Question: What causes voltage to fluctuate?

Respond: At that place could be several causes behind the issue:

bad alternator, bad voltage regulator, bad connections betwixt the battery and alternator.

First, make sure the connections are clean and tight, and the cables are good. Especially, check the grounds between the engine and trunk. Then, accept the alternator tested in your local auto parts store.

Question: I have a 1966 Ford Mustang and accept swapped out the alternator three times. Information technology will work fine at times, then at other times the voltage steadily drops, especially if I turn the lights on. The belt is good, connections are good. The battery is good. Any ideas as to what the problem could be?

Answer: Brand certain you lot accept clean and tight connections to the voltage regulator. If necessary, have the regulator checked. information technology might not exist sensing the voltage drop at the alternator when load increases. And the bombardment doesn't go the required accuse. Hope this helps.

Question: On my way home, the alternator lite came on but fabricated it abode fine. The next mean solar day, the truck was hard to crank and would only stay running if my foot remained on the gas. The side by side day, I charged the bombardment and put it dorsum in. Thought information technology was fixed but now the battery is dead and won't recharge. What'south the problem now?

Answer: Have the battery and alternator checked. If the alternator or charging system was faulty, it could've damaged the battery. Besides checking the charging system voltage drib may aid in the diagnosis.

https://axleaddict.com/auto-repair/Charging-System...

Question: What would crusade my alternator to be charging where it supposed to exist, so cause it to driblet all of the sudden? You can barely tap it and information technology goes back up.

Answer: Probably you are dealing with an alternator with worn brushes. Tapping the alternator shake the brushes a fleck and aid them make better contact or the copper wires continued to the brushes are damaged.

Question: Volition in that location be whatever signs in a Chrysler car battery terminal, if you remove the terminal that there is a problem with the alternator and charging system?

Answer: If the alternator is overcharging, there could be signs of corrosion; simply the terminal may be cracked or loose. Simply you may notice bug while the engine is running, but don't remove any connections while the engine is running. It can bear upon sensitive electronics. If you are trying to find a fault in the charging excursion connections, it'due south better to do a voltage driblet examination. This volition tell y'all the status of the connections. These other two posts may help you locate this type of issues with the charging system and engine grounds:

https://axleaddict.com/automobile-repair/Automotive-Volt...

https://axleaddict.com/auto-repair/Charging-System...

Question: I accept a 2011 Mazda 3, 2.5. The bombardment calorie-free turned on when I was driving at 120 km/h and would turn off if I slowed downward. The light now starts at ninety km/h and will turn off if I slow down (mayhap rpm related, non sure). Battery, alternator and first engine were tested at the dealership only seem to exist OK. The battery seems to slowly bleed within a few weeks as the speed decreases for the battery light to plow on. What could it be?

Answer: This may be an alternator event with worn brushes, slowly losing the power to charge the battery. A common test is to replicate engine rpm at which the light comes on. Watch the engine rpm when the battery low-cal comes on. At abode, with the transmission in Neutral or Park, increase engine speed to the same rpm and run across if the light comes on. If information technology does, the alternator needs new brushes.

Question: I accept a 1990 Ford F-150 and the alternator stays hot and won't charge the bombardment, any suggestions on what is wrong?

Answer: First, make certain the chugalug is properly installed, non slipping, and accessory pulleys are running OK. Check the charging system wires for loose or corroded connections or damaged wires. This other post may help here:

https://axleaddict.com/auto-repair/Charging-Organisation...

If necessary, accept the alternator checked (worn, bad voltage regulator) and bombardment. Hope this helps.

Question: I have a 2003 VW protrude. I have inverse the alternator more than eight times. I finally got the right 1 through the VW parts, simply it'due south still not charging back my battery, and I bought the bombardment a year and a half ago. I have been charging it and it still holding battery, so it'due south driving me crazy as to why is not working. Can you help?

Answer: The problem could be in the circuit. If your item model has a fuse (bank check your repair manual) information technology may be blown. Less likely, just it could happen, a fault in the computer can forbid the alternator from charging the battery.

Question: I have a new but cheap alternator. What could be causing such a big fluctuation in voltage?

Reply: The diodes could be leaking or shorted. Have the alternator checked before replacing information technology.

Question: I have a 2006 Ford Freestyle. Terminal year, the car didn't want to start, and then I replaced the battery. Five miles down the road, the bombardment lite came on. I took it to the Ford Dealership to check the problem. They replaced the Alternator. A yr later, I noticed the lights started to dim, then to fade back up. I took it to an Interstate battery shop to have the battery checked out. The battery was fantabulous, merely the alternator showed depression charge. What should I have the mechanics do side by side?

Answer: Although there is a remote possibility the alternator is failing, this may be a charging excursion (positive side) trouble. If you explain to the shop when you replaced the alternator and about the battery and alternator test results, most likely, they'll accept a expect into the charging circuit.

Question: What would crusade a new alternator to whine and have the pulley heat up excessively? Starting at ambient air and shooting upwards to 275+ degrees. But when the battery cables are disconnected while the engine is running, the alternator pulley runs polish and in that location is no excessive heat build upwardly. The battery is also brand new.

Answer: This is usually acquired by a faulty diode(due south), making alternator piece of work extra-hard. Check voltage output; besides, cheque the charge circuit voltage drib:

https://axleaddict.com/auto-repair/Charging-Organisation...

Question: I have a Nissan Wingroad and I had to supervene upon the battery before 18 months of use equally it wouldn't offset without jump starting. When the measures were taken, the charging organisation measures were xiii.560 volts on no load and loaded at 13.170. The bombardment vendor says that this indicates a charging system trouble, but my mechanic says that in that location is no trouble with those readings. The bombardment voltage was 14.09, cranking 10.590. What is the correct position, is there a charging problem or not?

Answer: Check the system specifications in your vehicle repair transmission. If you don't take the manual, your local public library may have a copy in the reference department. It'll exist more than curate and you'll avoid guessing. You can fifty-fifty do these measurements yourself with the manual. I don't take the manual for the model.

Question: I take a '03 Chevy Silverado alternator that whines and displays a bank check engine code, mainly knock sensor. Occasionally cylinder 7 and 8 are too lean. I suspect a bad basis. Do yous know where I can notice a visual of where all the grounds are on this truck?

Answer: If you don't have the repair manual for your specific model, check your local public library. They may take the transmission in the reference section. Alternator whining sounds may come bad bearings, bushing or misaligned, worn belt, even a bad diode on some models.

Question: Why does my '99 Bonneville's charging system go down to 12 volts just when in drive or while idling?

Answer: Usually, the voltage goes downward under load and as the engine warms up. But you might desire to check the alternator, battery and charging circuit if it dips below battery voltage. Having the charging system amperage may give you a better diagnostic of the charging organization, if necessary.

Question: Can the nuance charging gauge on a '67 Pontiac Catalina crusade the charging system not to work?

Reply: Information technology might cause problems with the regulator, only I don't have the schematics with me. If there are charging organisation bug, besides check that the wire and connections going to the starter are all good.

Question: I have a 2000 Civic EX 2 door coupe. The alternator went bad, and I replaced it along with the battery. The car runs fine. Information technology seems to accuse the battery, but then the battery light comes on. I take driven the motorcar, and I haven't had any problems running the AC, lights or radio. I can unplug the alternator, plug it dorsum, and the light will go out. Just as presently as I plug information technology in, the light comes on again. Doesn't seem to modify the engine running or idle when I unplug the alternator. What could be the trouble?

Reply: If at that place are whatever DTCs, articulate them from the computer memory. Also, check the fusible links. Make certain they are still well connected and adept.

Question: On my 2003 GT Mustang, when accelerating, my battery light flashes 3 times. I've replaced the battery, my belts are tight, and my alternator voltage is reading 14.lx v the first time I checked, and second time it was 13.90 v. Can't figure out what it is?

Answer: Check the connections. This other post may assist:

https://axleaddict.com/auto-repair/Charging-System...

Question: Bought a remanufactured alternator for my 2004 Civic today. I cannot go the wiring connector to snap back into the receptacle on the alternator. Can y'all give me some pointers, please?

Respond: Make sure the harness clip or connector is not damaged or broken. If the connector is OK, make certain you have the correct alternator for your detail model.

Question: I have a 2001 Toyota Solar, and the alternator keeps wearing out. Four out in a year in four years. It is a Toyota alternator, not an aftermarket. I have a new Interstate bombardment. 2 repair shops looked and didn't know why. Do you accept any thought what'southward going on?

Answer: Have your battery tested and likewise brand sure all battery cables and their corresponding connections between the alternator and starter are tight and clean.

If there'south too much resistance in the circuit, it'll clothing out your alternator. Besides, test the starter and charging circuits, if necessary.

Did they tell you how the alternator failed exactly? That can give you an idea near the consequence likewise. What most trouble codes? Scan the computer, just in case there are whatever pending codes.

Question: I take a 2004 Chevy truck and the gauge will stay at xiv volts just sometimes it'll drop downwards to 12 volts. Is this normal?

Answer: Check for a loose connection, wire or cable between the battery and the alternator. Wiggle the wires and encounter if the voltage changes. Also have the alternator checked, if necessary.

Question: I have a Toyota Corolla 2011. I just changed the alternator and battery a couple of months and the battery low-cal came on again. It's not charging at all would you say it'due south my alternator?

Respond: Information technology could be a faulty alternator or battery. However, the most common problem is in the circuit. Check the voltage driblet in the circuit. This other post may aid:

https://axleaddict.com/automobile-repair/Charging-Arrangement...

Also, bank check engine grounds, if necessary:

https://axleaddict.com/auto-repair/Automotive-Volt...

© 2017 Dan Ferrell

olsonwhavuld.blogspot.com

Source: https://axleaddict.com/auto-repair/Alternator-Problems-Troubleshooting

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