Voltage Read Going Down Alternator or Battery

Dan Ferrell writes well-nigh do-it-yourself machine maintenance and repair. He has certifications in automation and control applied science.

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

Photo courtesy of Pentti Immonen on Wikimedia

Alternator problems and charging organisation problems tin can touch on your vehicle in different ways. Yous may observe:

your ALT or Charge indicator low-cal comes on,
your engine is hard to outset and cranks slowly, or doesn't crank,
your bombardment demands lots of h2o,
your alternator makes noises,
or your headlights suddenly get dim.

These and other problems may be caused by a fault in the charging organisation.

Before you start replacing components with the hope of fixing the problem, you need to determine which component or components are causing you trouble. Oftentimes, it is possible to diagnose and solve the trouble on your own using a few simple tests and tools.

The sooner you find out what is causing trouble, the amend. You lot'll prevent a faulty component from ruining other parts in the system, which would make your repair more expensive.

This convenient troubleshooting guide will help you detect out what you demand to know, using a few unproblematic checks you can do at home using a test light or digital multimeter (DMM) and possibly a few other common tools.

It is a skilful thought to accept on mitt the vehicle repair manual (or a good aftermarket manual) for your particular car make and model. It will help you place wires, specific components, and possibly suggest some specific tests recommended past your manufacturer.

If you want to test the status of the system as a diagnostic starting betoken, do the tests described in the following section, "General Charging System Check."

However, if you lot need assistance for a specific problem with your charging system—for case, an over-charge or under-charge status, discharging battery, or noisy system—then skip over to the "Charging System Problems and Potential Causes" section.


Alphabetize
I. Common Symptoms of a Bad Alternator or Charging System
2. Full general Charging Organisation Checks
III. Charging System Bug and Potential Causes
IV. Troubleshooting for Unusual Voltage Organisation Drops

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

Photograph courtesy of Kskhh on Wikipedia

I. Mutual Symptoms of a Bad Alternator or Charging Organisation

Indicator Calorie-free On

Normally, the first sign that your charging system is in trouble is a "bombardment," "ALT," or "Charge" warning light illuminating on your instrument panel while driving. It ways that the alternator voltage output is below 12 volts, or over its limit or has stopped charging the battery and your car is running on battery power.

If the low-cal illuminates only intermittently, information technology usually indicates a loose or worn bulldoze belt or serpentine belt, worn-out or bad carbon brushes in the alternator. But remember that the calorie-free doesn't always mean at that place is a bad role; the calorie-free may be triggered by a sensor giving a wrong bulletin or at that place'due south something wrong with the circuit itself.

II. Six Tests for the Charging Organisation in Full general

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

one. Make a Visual Inspection of the System

With the engine off, pop the hood open and visually audit the different components of the charging organisation. Await for a worn out or loose drive chugalug, alternator connection problems, loose alternator mounting bolts, and corrosion and dirt around the battery example and cables.

When inspecting the bulldoze belt, check for adjustment. If necessary, adapt the belt with the help of your car possessor'due south transmission or repair manual. Inspect the chugalug for signs of cracks, cuts, shiny spots, deterioration or other signs of wear or damage. Change the belt and belt tensioner at the manufacturer's recommended interval.

2. Check for Wiring Problems

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.

three. Exercise This If the Indicator Light Stays On, or Goes On and Off

Follow the adjacent steps:

Start the engine and apply the emergency brakes. Set the manual to Neutral (manual) or Park (automatic).
Connect a voltmeter across the battery terminals.
While watching the voltmeter display, start wiggling wires at the back of the alternator, the bombardment, and the remote voltage regulator (if there is one).
If the voltage reading on the meter display goes up while wiggling one of the wires, y'all've plant a bad electric wire or connexion.

Instead of using a voltmeter, you can have an banana lookout man the indicator light on the musical instrument panel to meet if it turns off as you lot jerk various wires and connectors. Once the lite turns off, yous've found the trouble connector or wire.

four. Check for Alternator Noises

Bad alternator bearings, rectifiers, rotor shaft, stator winding, skid rings, brushes and other parts inside the alternator with mechanical or electrical bug can go noisy.

Here'southward a test you can do: Use a length of vacuum hose to listen for alternator noises. The hose will amplify the noise if it's coming from the alternator. But be very careful effectually moving parts while you do this exam.

Beginning the engine.
Place one finish of the hose against your ear and motion the other end around different points of the alternator body.
Mind for whining noises (this can indicate a bad diode or an over-charging status), grinding (bad begetting), squealing, or other aberrant noise. If necessary, have your alternator checked.

5. Check for Nether-Charging and Over-Charging

The next iii tests are best done using a load tester, but you yet can apply your digital voltmeter. Y'all do this by measuring system voltage while loading the system.

5a. First, measure bombardment base of operations voltage to brand sure yous accept a fully charged battery.

Turn on the high beams for 10 seconds and so turn them off.

Wait for two minutes

Measure out battery voltage across the battery posts with your DMM. You should get between 12.4 and 12.6V. This means your battery is fully charged. If you get a reading below 12.4V, accuse the battery before continuing.

5b. Measure the Charging Organization's No-Load Voltage

Ask an banana to first the engine and hold engine speed at about 1500 RPM.

Measure out voltage beyond the battery with your DMM. You should get 0.5 to 2 volts higher than base voltage. If y'all are getting more than ii volts higher up base voltage, well-nigh likely your alternator is over-charging the battery or the battery is faulty. Other potential issues are a faulty voltage regulator or a problem in the charging system wiring. As function of your wiring checks, see the department "Troubleshooting for Unusual Charging System Voltage Drops" below.

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

Ask an assistant to get-go the engine and hold engine speed at near 2000 RPM. Turn on all electric accessories like A/C, blower motor, headlights, defroster, wipers. Just don't plow on the heated windshield if your vehicle has one; alternator voltage may increase to over 100V and this can be unsafe.

Take a voltage reading across the battery posts. Your reading should be at least 0.5 volts to a higher place base of operations voltage for your system to keep up with electrical system demands. Otherwise, the charging system can't meet the demand and accuse your battery. This fault could point to a faulty alternator or voltage regulator. Check the section "Troubleshooting for Unusual Charging System Voltage Drops" beneath to check for wiring problems that can lead to this condition.

Notation: These measurements correspond to an ambience temperature of about 70º F. The charging voltage will increase equally temperature drops, and charging voltage will subtract as temperature goes up. Then keep this in heed when making your measurements.

6. Cheque for Alternator Air-conditioning Voltage Leak

Alternators apply diodes to rectify alternating electric current produced by the alternator into direct current. When one or more diodes get bad or a stator winding fails, the alternator can cause all kinds of problems. Ac voltage leak tin can cause your lights to dim and drain power from your battery, for example. Usually, you can detect this leak past measuring Air conditioning voltage at the alternator.

Start and let the engine idle.
Set the parking brake and your transmission to Park (automatic) or Neutral (manual).
Set your meter to a depression Ac voltage range.
Ask an assistant to increase engine RPM to 2000 rpm.
Bear on the ruby-red meter lead to the alternator bombardment terminal B+.
Touch the blackness meter lead to the alternator case (ground).
If your DMM reads 0.4 AC volts or less, the diodes are good.
If your DMM reads 0.5 AC volts or more, the diodes or stator is faulty.

One time you've determined the condition of the system, you can go over the side by side section to zero in on the potential trouble(south) that may be causing the status of the charging system.

A single bad battery cell can prevent your charging system from working properly. — A single bad bombardment jail cell tin can foreclose your charging system from working properly.

Photo in the public domain.

Three. Charging Organisation Bug and Potential Causes

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

i. If the Battery Seems to Stay Undercharged

You have already charged your battery a couple of times and y'all just establish out the bombardment is undercharged again. Before you arraign your bombardment, or the alternator, here are some preliminary checks you lot may want to practise.

a) Bank check the bulldoze chugalug or serpentine belt, specially if you oasis't replaced information technology in the last five years. Make sure the chugalug has the proper tension. Look for signs of wear or damage 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 wear indicator or check your maintenance schedule for the replacement interval suggested past your car manufacturer. You may find the schedule in your car owner's manual or your repair manual.

b) Forth with the drive chugalug, check the belt tensioner likewise. Make sure information technology turns freely and is noise-gratuitous. Machine manufacturers recommend replacing the tensioner at the same time you lot replace the bulldoze chugalug.

c) Make certain your battery connections are tight and clean. Notwithstanding, just because the terminals look clean, it doesn't mean they are tight and in proficient condition. Look for damage to the cablevision and the last itself that may prevent proper electrical current flow.

d) Bank check your bombardment yourself, or accept it to your local auto parts store. Many of these stores will test your battery for free.

e) There'south a parasitic battery drain stealing power from your bombardment.

A quick exam is to connect a test calorie-free in serial between the positive battery cable and the positive bombardment post. If the test light comes on, in that location is an electric bleed in one of the systems.
First, unplug the alternator electrical connector. If the test light 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 electric current during operation, draining bombardment ability. If necessary, accept your starter motor or starting system tested.

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

h) At that place could be an alternator wiring trouble.

i) Have the alternator and bombardment checked.

2. If the Organisation Seems to Be Over-Charging

Besides exam results, another potential sign that your battery is being overcharged is that your battery terminals go along 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 clean, tight and in good condition.
Cheque your battery or have it tested at your local auto parts store. A bad battery prison cell can cause the alternator to over-charge the good bombardment cells.
Check for a bad alternator voltage regulator and circuit. Consult your vehicle repair manual, if necessary.
Brand sure y'all have good ground connections at the alternator (alternator case) and voltage regulator, especially if your vehicle uses a remote voltage regulator. Grounds should exist gratuitous of rust, and the alternator and remote voltage regulator mounting bolts should be make clean and tight.
Check the alternator rectifier or have your alternator checked at the motorcar parts store.
Likewise, conduct the tests described in the Troubleshooting for Unusual Charging Organisation Voltage Drops below.

3. If the Alternator Is Not Charging the Bombardment

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

Make sure the bulldoze belt is non loose or worn out.
If necessary, borrow a good bombardment just to operate the engine and confirm that your drive chugalug and chugalug tensioner are operating properly.
Manually check the belt tensioner for proper operation. Make sure the tensioner pulley turns freely and without noise. Check it for damage.
Manually plough the alternator pulley and make sure it turns without a problem. If ane of the bearings has seized, it 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 blown 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 System Voltage Drops" below.

4. If the Engine Makes Noises

Dissonance tin can exist a sign of alternator issues when it comes from the charging system. The adjacent checkpoints will help you isolate the source of the noise.

Check the drive belt or serpentine chugalug. Look for signs of vesture or impairment similar cuts, shiny spots or missing chunks nether the belt. A worn out belt can squeal during operation.
Also, check the belt tensioner for proper operation and damage. It should rotate freely.
Make sure the alternator is properly mounted. Loose mounting bolts tin cause the alternator bulldoze chugalug and drive pulley to get misaligned and noisy.
Check the alternator for noises. See the Full general Charging Organisation Checks section for a unproblematic process for this.

five. If Lights Dim During Engine Performance

Most alternators apply diodes inside a rectifier to plow Alternating Current (AC) into Straight Electric current (DC) for use by the organisation. When 1 or more than diodes go bad, AC tin leak into the electrical organization. Sometimes you can find this when the headlights, instrument panel lights, and other interior lights dim during engine performance. To test your alternator for AC current leaks, see the Alternator Air conditioning Voltage Leak Check subsection in the previous department.

Measure system voltage and drop voltages using a digital multimeter. — Measure out 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 system voltage driblet check can help you locate the source of an under-charge or over-charge status due to bug in the wiring or connections between the battery and alternator.

1. Start the engine and permit it idle. Apply the parking brake and set the transmission to Neutral (manual transmission) or Park (automatic transmission).

2. Turn on the high beams to provide a system load. And have an banana raise engine speed to nigh 1500 RPM. If your vehicle is equipped with a heated windshield, don't turn it on; this tin brand alternator voltage go over 100 5. Since you'll exist working around alternator connections, this could be dangerous.

3. With your voltmeter test leads, touch the positive bombardment post and the B+ last connector at the back of the alternator.

four. Check your meter brandish. Yous should get around 0.4V or less of voltage drop. If your voltage driblet is college, it tin can lead to an under-charge condition. Check the connections in that part of the excursion for a loose wire, corrosion at the connectors or wiring harm that may prevent proper current period betwixt the bombardment and alternator. Also, check the electrical connections at the back of the alternator and at the voltage regulator.

5. At present repeat the test, but this time, connect your meter leads betwixt the battery negative post and the alternator case.

6. Check your meter display. Again, you should get a voltage reading around 0.2V or less. If your voltage drib is higher, there'due south something wrong. This tin can atomic number 82 to an over-charging status. Checking that part of the excursion, make sure the battery ground connectedness is skilful, make clean and tight. Add together a temporary ground connection from the bombardment to the chassis. If this removes the high voltage drib, check the engine to body grounds connections. They should be clean, tight and in good condition.

Watch the side by side video for a visual reference on voltage driblet checks.

Alternator problems are not uncommon later a few years of performance. A typical alternator may terminal anywhere from 8 to 12 years. So don't be surprised to find your alternator going bad or the system developing problems subsequently a few years of trouble-free operation, even if yous accept maintained your car well.

The primal point here is to do the proper diagnostic equally soon as possible because a bad alternator can ruin an otherwise proficient battery, and other components likewise, depending on the error.

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

This content is accurate and truthful to the best of the writer's cognition and is not meant to substitute for formal and individualized advice from a qualified professional.

Questions & Answers

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

Answer: The problem could exist in the charging circuit. This other post may help:

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

Question: I got a 2012 Nissan Xterra. I simply installed a new alternator and new bombardment. It starts up good and idles proficient at present too, but when I give information technology total throttle and become close to 3,000 RPMs, my bombardment light and park brake lights comes on and flashes at me. And the battery volt gauge goes downward a whole lot. What could be the trouble?

Answer: Check the alternator chugalug and tensioner. Belt should have the proper force per unit area. If it'south loose, it won't charge properly during hard accelerations. Check voltage at the battery when accelerating (at idle and emergency brakes applied). Y'all should get effectually 13.five or then. Otherwise, there could exist a problem with the voltage regulator. You may need to replace the alternator. If not, check 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. Information technology'south charging but information technology'southward charging slowly. It'southward running at 12.80 volts constantly. I'm out of ideas?

Respond: Cheque the connections. A loose, corroded or damaged wire or connectedness tin can cause this type of problems:

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

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

Question: I use a Golf four alternator on a Golf 4 as I saw fit. It runs fine, and there aren't any alarming sound. The problem is that information technology doesn't accuse when I start the car. I accept to rev the engine hard, and and so it starts to charge ordinarily. What the problem?

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

Check the drive chugalug outset for tension and wear. Also, make sure that the back wires are properly continued and clean. Then, bank check the voltage regulator.

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

Reply: Check your battery and excursion between the battery and alternator. As well, check if there are any modifications to the organization?

Question: Battery tested fine, merely alternator voltage would go upwards and down. Occasionally, a Battery SYSTEM FAILURE light volition come on. Could information technology exist a sensor/fuse problem since it doesn't stay on all the time?

Answer: The alternator could be faulty. Only y'all may want to run a voltage drop test on the excursion outset. Some models, like GM, take a fusible link in the circuit. Make sure that it's good. This other mail has a voltage drop section that may assistance:

https://hubpages.com/machine-repair/Charging-System-C...

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

Answer: My judge is the Air-conditioning pulley may exist putting a strain on the crankshaft caster, affecting alternator output. Or the AC pulley is affecting the belt. Cheque how the three operate when the Air conditioning is on.

Question: I have an 04 Lincoln aviator. I changed the battery, alternator and I am still getting a check charging arrangement message. What do I exercise next?

Reply: Make sure you lot actually take a charging problem. Your local auto parts shop can check the alternator and battery for y'all. If there'south a problem, it could be in the circuit. If not, the excursion for the alarm light might be the issue.

Question: I accept 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 flat. I wiggled the wires going to the alternator and it struck upwardly easily. Practise these symptoms mean the alternator is no good?

Answer: Bank check showtime the wires for a loose or dirty connectedness; frayed wires, etc.. Checking voltage driblet on the connections and wires tin help a lot to locate faulty connectors and wires. This other mail service may help.

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

Question: I take a 06 Mustang GT. I replaced the alternator because information technology was causing a camshaft position sensor code. After replacing information technology and checking my work, the battery light with a warning "check charging system" comes on. It comes on for a minute or then then goes out for a few minutes. The battery seems to stay effectually 13.7 volts what could be causing the low-cal to come on randomly? I have not driven it yet.

Answer: Check the circuit connections. This could be a loose or bad wire/connector. You may want to try a voltage drop test. This postal service gives you an thought of the examination:

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

Question: I have a 2001 Toyota Solara with 158,000 miles. I've gone through 5 alternators in nigh 6 yrs. Even the Toyota oem. Ii reliable mechanics can't figure it out. I'chiliad taking information technology to a shop that specializes in electrical problems. Do y'all have any ideas?

Answer: Knowing how the previous alternators failed can give a inkling almost the type of upshot you are dealing with (electrical, mechanical). Usually when alternators failed prematurely is because of a bad bombardment (electrical), voltage regulator issues, high electric loads (e.g. running Ac fan at high) or a drive belt that is putting unusual stress on the alternator pulley (mechanical)(make sure the belt is not too tight). Alternator quality can exist some other factor of grade.

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

Question: I accept a good alternator, but my battery runs down. It passed tests performed at two auto parts stores. When this problem occurred, I was able to get dwelling past starting the vehicle (2000 GMC Yukon, v.3L) by disconnecting the battery. Voltage when up close to fourteen according to the guess. When I reconnected the batter at home, it was however expressionless. Got a new battery and take the aforementioned problem with battery bleed. Practice you accept whatever ideas?

Answer: If you lot have some power amplifier, or some other power accessories, this could be running down the battery if the alternator tin't keep up with the demand. Other than that, you may want to have the alternator checked in a store, and come across where the charge is going while the engine is running.

You tin can bank check for a parasitic drain that yous may not exist aware of. This mail service can help you:

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

Question: I installed a new 105-amp alternator in my 1982 Chevrolet C10. When I beginning the engine, it indicates 14.half dozen volts on the voltmeter continued to the battery. When I start the AC fan and the Air-conditioning compressor, the voltage increases to 15.viii volts. After a while, the alternator stops charging; I think information technology might exist defective. I changed two alternators, but I still accept the same problem. What practise yous think?

Reply: Check the voltage regulator and the battery. An car parts store may check the battery for yous. Also, may sure the circuit connections for the charging system are clean and tight and cheque the engine body grounds.

Question: I take a 2004 Taurus, and I've inverse the battery and alternator but the charging organisation light is still on. Any ideas why?

Answer: Bank check the fusible link, you can test it with your multimeter.

Question: I have a 2005 Ford Taurus i 24-hour interval it wouldn't starting time. It finally started and flashing lights to check the restriction organization in the charging system, simply and then it wouldn't start once it was jumped. It kept stalling, so we had it checked at an automobile parts store. They agreed alternator replaced the alternator and it is still doing the same thing do you take 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 can eventually, damage the alternator. Test for voltage driblet on the grounds, battery and charging system.

Question: I had my alternator rebuilt. Now I am having a problem getting it to charge at idle, I get 14.5 volts at 1500 rpm, but equally soon as 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, only on the car, it'southward doing exactly as I mentioned before, no voltage at idle, full voltage when revving the engine. Could this be a PCM issue?

Answer: Check the belt and belt tensioner for the correct tension. Take a look at the connections at the dorsum of the alternator, especially the B+ connector. On early on models the indicator light on the dashboard should come up on when the ignition central is in the On position, otherwise, you'll take problems at idle. There could also be a problem in the charging circuit, a loose, corroded or damaged wire can also prevent full voltage at low 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/automobile-repair/Automotive-Volt...

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

Question: Our engine will accept likewise much time to first. How can I check the alternator?

Reply: The problem might be with the bombardment, starting system, ignition or fuel system. Cheque the concoction condition, check for spark and fuel pressure.

Question: I have a Toyota Corolla VVTI model 2004, I have changed the alternator just the bombardment indicator is still nowadays. I have checked the fuses and connections, only the problem continues. What could be the issue?

Answer: Have the battery tested, and bank check the connections in the charging organisation. Make sure they're make clean and tight. Besides, the check the engine grounds.

Question: My voltage is fine when I start the vehicle, but after driving around for about 10-15 minutes, my voltage goes from 14v to 15.5-16v. I accept an aftermarket voltage regulator, and a high output 320 amp alternator and my battery dies if I don't unhook the wire from my battery to the cars fuse box. Do y'all have any ideas?

Answer: You need to brand sure the alternator is suited for your application. These alternators need the right caster ratio and pulley bore 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 automobile and it says my charging organization output is high. What does that mean exactly?

Answer: This basically means the alternator is overcharging the bombardment. Usually the trouble here is the voltage regulator. Before replacing the alternator, you tin take the alternator to a local auto parts store and have them check it for yous. Brand sure the alternator is the problem.

Question: What are the most common faults likely to occur in a charging arrangement? More than 6 points at least.

Answer: There can be a problem with the excursion, voltage regulator, ignition switch, corroded bombardment cables, faulty battery, worn or loose bulldoze belt, bad car figurer.

Question: I take a 2014 Nissan Pathfinder. I inverse my alternator in July 2018. Alternator stopped working again on 2/6/2019 and replaced it on 2/7/2019. Back in the store on two/xi/2019 with bad alternator again. This time the alternator is overcharging. The alternators were bought from O'Reilly'south auto parts. Merely plant out they are rebuilt alternators, and not new. Still, the toll was $400 for the role. Could there be something causing the part to get bad so quick or could it just happen to be bad parts?

Answer: Make sure y'all are using the correct bombardment for your awarding. On some newer models using the incorrect battery tin can affect the alternator, especially those that interact with the ECU. Also, check the belt and pulleys. Brand sure the pulleys are correctly aligned, and the alternator is properly mounted without rust accumulation, especially the ground connections, including engine and battery grounds. As well, check the wiring for signs of electric faults. And yes, some models are very sensitive to using parts other than OEM, but first, make the previous checks.

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

Answer: You might desire to make a voltage drop test on the charging circuit. There could be a bad connection or wire that is non too evident. This other mail service will give yous an idea on how to become about the exam:

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 1, now information technology went downwards. What is the problem? I have besides noticed the positive battery post on my bombardment gets hot. Do you have any idea what it could be?

Answer: There could be also much resistance on that side of the circuit. Check the cable for damage, or a problem at the connectors. If everything seems okay, have your battery tested.

Question: I have a 2003 VW Eurovan. Recently, the ABS light went on, then, later on a few minutes the regular cerise brake low-cal lit and the car stopped. What is going on?

Answer: You demand to download the trouble codes. There could be a number of things that triggered the ABS low-cal - problems with the tone ring, wheel bearing, speed sensor (and wiring).

Question: I take a GM 3500 6.0 with an overcharging trouble. 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 too. Just it is still charging to 15.vi-xvi.0. What could possibly be going wrong with my car's alternator?

Answer: The problem could exist on the ground side of the circuit. Increased resistance (loose, corroded grounds) can cause this type of trouble. Of form, you want to make certain yous got the correct alternator for your application. This other post may assist:

https://axleaddict.com/car-repair/Charging-Organization...

Besides, make sure to scout this other video:

https://world wide web.youtube.com/watch?v=OqylgRKiC-A

Question: I have a 2012 Town and Country with 110k miles. Last year at around a 100k miles I replaced the alternator due to regulator failure. This yr I installed a new bombardment. The problem is the charging lite comes on randomly. I drive around with a voltmeter to run these tests the moment it happens, but everything checks out. Why does the light come on and non go out?

Answer: Check the chugalug. A worn belt may slip intermittently, affecting the charging system. The trouble with newer belts is they wait good even if they are worn. Check the belt for tension and wear (use a belt wear estimate), tensioner, pulleys, and grounds, and specially engine grounds.

Question: I accept an 03 Dakota. It needed a new battery, however, the battery gauge goes to 0, and the idiot light comes on later on I drive information technology for a minute. It starts fine and the lights are fine; just that gauge quits working. What causes that?

Answer: Check the alternator, peradventure a bad voltage regulator.

Make sure the bulldoze belt is not loose or the idler bad, causing the belt to slip. If the battery accuse is non affected and everything else seems to piece of work just fine, there could exist a loose wire or connector in the excursion to the approximate.

Question: I have a 2007 Cadillac CTS. I replaced the bombardment, cranked upwardly and the negative connection got hot. What would cause my Cadillac's bombardment to estrus up?

Answer: If the negative cable gets too hot just cranking the engine, there's too much resistance in that part of the excursion. If this happened right after installing the new battery, probably the negative cablevision is non well connected or is damaged or in that location'due south some corrosion. Yous tin can also do a voltage driblet test on that part of the circuit. These posts may help:

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

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

Question: What causes voltage to fluctuate?

Answer: There could be several causes behind the issue:

bad alternator, bad voltage regulator, bad connections between the bombardment and alternator.

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

Question: I take a 1966 Ford Mustang and have swapped out the alternator 3 times. Information technology will piece of 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 skilful. Any ideas every bit to what the problem could be?

Answer: Brand sure you have clean and tight connections to the voltage regulator. If necessary, have the regulator checked. information technology might not be sensing the voltage drop at the alternator when load increases. And the battery doesn't become the required charge. Hope this helps.

Question: On my way dwelling, the alternator light came on but made it home fine. The next 24-hour interval, the truck was difficult to crank and would just stay running if my foot remained on the gas. The next twenty-four hour period, I charged the bombardment and put it dorsum in. Thought information technology was fixed just at present the battery is dead and won't recharge. What'southward the problem now?

Reply: Accept the bombardment and alternator checked. If the alternator or charging arrangement was faulty, it could've damaged the battery. Too checking the charging arrangement voltage drop may help in the diagnosis.

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

Question: What would cause my alternator to be charging where it supposed to be, then cause information technology to drop all of the sudden? You can barely tap it and information technology goes back upwardly.

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

Question: Will in that location be any signs in a Chrysler car bombardment terminal, if y'all remove the concluding that in that location is a trouble with the alternator and charging system?

Answer: If the alternator is overcharging, in that location could be signs of corrosion; but the last may be cracked or loose. But you may find problems 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 discover a mistake in the charging circuit connections, it's better to do a voltage drop test. This will tell you the status of the connections. These other two posts may assist yous locate this type of problems with the charging system and engine grounds:

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

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

Question: I take a 2011 Mazda 3, ii.v. The battery lite turned on when I was driving at 120 km/h and would plow off if I slowed down. The light at present starts at 90 km/h and will turn off if I dull downwards (possibly rpm related, not sure). Battery, alternator and showtime engine were tested at the dealership simply seem to exist OK. The bombardment seems to slowly drain within a few weeks as the speed decreases for the battery light to turn on. What could it be?

Reply: This may be an alternator issue with worn brushes, slowly losing the ability to accuse the battery. A common test is to replicate engine rpm at which the calorie-free comes on. Watch the engine rpm when the battery light comes on. At dwelling house, with the manual in Neutral or Park, increment engine speed to the same rpm and run into if the light comes on. If it does, the alternator needs new brushes.

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

Respond: First, brand certain the belt is properly installed, not slipping, and accompaniment 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/car-repair/Charging-System...

If necessary, have the alternator checked (worn, bad voltage regulator) and battery. Promise this helps.

Question: I have a 2003 VW beetle. I have changed the alternator more 8 times. I finally got the correct one through the VW parts, simply information technology's nonetheless not charging dorsum my battery, and I bought the battery a year and a one-half ago. I have been charging information technology and it still belongings battery, so it's driving me crazy equally to why is non working. Can you lot help?

Reply: The problem could be in the circuit. If your particular model has a fuse (cheque your repair manual) it may be diddled. Less probable, but it could happen, a fault in the computer can preclude the alternator from charging the battery.

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

Answer: The diodes could be leaking or shorted. Have the alternator checked earlier replacing it.

Question: I take a 2006 Ford Freestyle. Last yr, the car didn't want to first, and then I replaced the bombardment. 5 miles downwards the road, the battery lite came on. I took it to the Ford Dealership to bank check the problem. They replaced the Alternator. A twelvemonth later, I noticed the lights started to dim, then to fade back upwardly. I took it to an Interstate bombardment shop to have the battery checked out. The battery was fantabulous, only the alternator showed low accuse. What should I have the mechanics do next?

Answer: Although there is a remote possibility the alternator is declining, this may exist a charging circuit (positive side) problem. If you lot explain to the shop when you replaced the alternator and about the battery and alternator test results, most probable, they'll accept a look into the charging circuit.

Question: What would cause a new alternator to whine and have the caster estrus up excessively? Starting at ambient air and shooting upward to 275+ degrees. Merely when the battery cables are disconnected while the engine is running, the alternator pulley runs smooth and there is no excessive heat build up. The battery is also brand new.

Answer: This is commonly acquired past a faulty diode(south), making alternator work extra-hard. Check voltage output; besides, check the charge circuit voltage drop:

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

Question: I accept a Nissan Wingroad and I had to replace the battery earlier xviii months of employ every bit it wouldn't start without jump starting. When the measures were taken, the charging arrangement measures were 13.560 volts on no load and loaded at 13.170. The battery vendor says that this indicates a charging system trouble, just my mechanic says that there is no problem with those readings. The battery voltage was 14.09, cranking 10.590. What is the correct position, is there a charging problem or non?

Answer: Check the organisation specifications in your vehicle repair manual. If you don't have the manual, your local public library may have a copy in the reference section. It'll exist more than curate and y'all'll avert guessing. You can even do these measurements yourself with the manual. I don't have the manual for the model.

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

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

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

Answer: Usually, the voltage goes downwards under load and as the engine warms up. But you might want 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 arrangement, if necessary.

Question: Tin can the nuance charging judge on a '67 Pontiac Catalina crusade the charging organization not to piece of work?

Answer: It might cause problems with the regulator, but I don't accept the schematics with me. If there are charging system issues, also check that the wire and connections going to the starter are all expert.

Question: I have a 2000 Borough EX two door coupe. The alternator went bad, and I replaced information technology forth with the battery. The auto runs fine. It seems to accuse the battery, but then the battery calorie-free comes on. I take driven the automobile, and I oasis't had any problems running the AC, lights or radio. I can unplug the alternator, plug it dorsum, and the light will go out. Merely equally presently every bit I plug it in, the light comes on again. Doesn't seem to change the engine running or idle when I unplug the alternator. What could be the problem?

Reply: If there are any DTCs, articulate them from the computer retentivity. Also, check the fusible links. Make sure they are still well connected and good.

Question: On my 2003 GT Mustang, when accelerating, my bombardment light flashes 3 times. I've replaced the battery, my belts are tight, and my alternator voltage is reading 14.60 5 the showtime time I checked, and second time it was 13.90 v. Can't effigy out what it is?

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

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

Question: Bought a remanufactured alternator for my 2004 Civic today. I cannot get the wiring connector to snap dorsum into the receptacle on the alternator. Can you give me some pointers, please?

Respond: Make sure the harness clip or connector is not damaged or broken. If the connector is OK, make sure you accept the right alternator for your particular model.

Question: I have a 2001 Toyota Solar, and the alternator keeps wearing out. Four out in a year in four years. Information technology is a Toyota alternator, not an aftermarket. I have a new Interstate battery. 2 repair shops looked and didn't know why. Practice you have whatsoever thought what's going on?

Reply: Have your battery tested and too make sure all battery cables and their respective connections between the alternator and starter are tight and clean.

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

Did they tell you how the alternator failed exactly? That can requite y'all an thought about the issue also. What about trouble codes? Scan the computer, just in case there are whatever pending codes.

Question: I accept a 2004 Chevy truck and the gauge will stay at 14 volts but sometimes it'll drop downwards to 12 volts. Is this normal?

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

Question: I have a Toyota Corolla 2011. I simply changed the alternator and bombardment a couple of months and the battery light came on again. Information technology'south not charging at all would you say information technology's my alternator?

Answer: It could exist a faulty alternator or bombardment. However, the nigh mutual problem is in the excursion. Cheque the voltage drib in the excursion. This other post may aid:

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

Likewise, check engine grounds, if necessary:

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

edwardsnough1952.blogspot.com

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

Voltage Read Going Down Alternator or Battery

I. Mutual Symptoms of a Bad Alternator or Charging Organisation

Read More from AxleAddict

II. Six Tests for the Charging Organisation in Full general

Three. Charging Organisation Bug and Potential Causes

Iv. Troubleshooting for Unusual Charging System Voltage Drops

Questions & Answers

0 Response to "Voltage Read Going Down Alternator or Battery"

Post a Comment

Iklan Atas Artikel

Iklan Tengah Artikel 1

Iklan Tengah Artikel 2

Iklan Bawah Artikel