There are essentially three ways to make an alternator repair (either by the mechanic or yourself):
- Replacing the old alternator with a brand new one
- Replacing the old alternator with a used or refurbished one
- Refurbishing (repairing) your old alternator
Full Answer
How do you tell if the alternator needs replacing?
The Warning Signs of a Failing Alternator
- Indicator Lights. Most modern cars have a dashboard warning light to alert you to a problem with your alternator. ...
- Headlight Trouble. Your alternator provides the power to your headlights. ...
- Other Electrical Problems. ...
- Smells. ...
- Dead Battery. ...
- Stalling or Difficulty Starting. ...
- Noises. ...
How to easily diagnose a bad alternator at home?
- Start the vehicle (it'll start and stay running if you have charged the battery.)
- Put the red multimeter test lead on the battery positive terminal.
- Put the BLACK lead on the battery negative terminal.
- Look at the reading. It should hover around 12 Volts.
How to make replacing an alternator easy?
In addition to a replacement alternator, you’ll need some tools:
- Hand tools like ratchets, sockets, and wrenches
- Belt tensioner tool
- Gloves and safety gear
- Battery tender or memory saver, if necessary
- Jack, jack stands, and wheel chocks, if necessary
How hard is it to replace an alternator?
How to Test Your Alternator
- Turn your multimeter on and set it to "voltage." If it has specific voltage settings, you want it to be able to test up to at least 20 volts.
- Before you turn the car on at all, look for a large red wiring attached to a terminal on the back of the alternator. ...
- Next, keep the positive probe (+) on the alternator terminal. ...
How can I make my alternator work again?
2:554:34How to Fix a Dying Alternator for Free - YouTubeYouTubeStart of suggested clipEnd of suggested clipBut you don't have to hit it hard you don't have to beat the living crap out of it. But. If you doMoreBut you don't have to hit it hard you don't have to beat the living crap out of it. But. If you do it. Right. You'll get your alternator to start working again.
Can you fix a bad alternator?
Some alternator parts can be easily replaced such as bearings. These can fail due to inadequate lubrication or excessive wear. Wiring connections can become loose or even break, disrupting electrical output. In some cases, these may be able to be soldered back together and repaired.
Can you fix an alternator at home?
Replacing an alternator can cost you several hundred bucks at the local repair shop, but it's one of the simplest repairs you can do at home. With a few tools and about an hour you can swap it out yourself -- and keep your dough in your pocket where it belongs.
How do you fix an alternator that is not charging?
Check the large power cable to the alternator and the fuse, usually, a large 40-60 amp fuse near the battery. Check the ground cable between the engine and the body. Check the serpentine belt and make sure the alternator is spinning with the engine. Check the small power supply wire and the charging light wire.
What kills an alternator?
Running in full charge mode continuously can kill an alternator, so trying to have your new alternator try and charge your dead battery can result in immediate alternator failure.
What causes alternator failure?
Most of the time, alternators fail as a result of age or use. However, some other factors can cause an alternator to fail prematurely. Fluid leaking on the car alternator can commonly lead to failure. Often, engine oil or power steering fluid can work its way into the alternator and cause it to malfunction or fail.
Is it worth rebuilding an alternator?
Rebuilt Will Cost Less You could save up to about half on a rebuilt alternator. In this process the broken parts are replaced, hence the term rebuilt. You may get up to a 90-day warranty. Remanufactured alternators still offer some savings, around 25% generally, and are different than rebuilt ones.
Is it better to rebuild or replace an alternator?
Rebuilding an alternator is a more involved process. The alternator is dismantled and inspected. Internal electrical and electronic components are tested. Parts that are known to have a relatively short life may be replaced without testing.
How much does a new alternator cost?
Typically, it costs between $400-$600 to replace a faulty alternator with parts and labour. However, this price usually reflects a remanufactured alternator. New alternators can run you approximately $500 to $1000, again, depending on the type of vehicle you have.
Is there a fuse for a alternator?
Your car contains a wide range of fuses, including fuses for the alternator. The primary alternator fuse (or fusible link) will blow whenever there's excessive current flow due to a short circuit or other malfunction.
How do I know if my alternator fuse is blown?
0:261:57Car Battery Dead? Check Your Alternator Fuse - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo if the fuse is bad it's most likely gonna have physical signs of burning or melting.MoreSo if the fuse is bad it's most likely gonna have physical signs of burning or melting.
How do you diagnose an alternator problem?
7 Signs of a Failing AlternatorDim or Overly Bright Lights. ... Dead Battery. ... Slow or Malfunctioning Accessories. ... Trouble Starting or Frequent Stalling. ... Growling or Whining Noises. ... Smell of Burning Rubber or Wires. ... Battery Warning Light on Dash.
Tips
When installing a new volt regulator, be sure to apply thermal grease to the back of the apparatus.
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What to do if your alternator battery dies?
If your battery dies, you should test the battery (free at AutoZone). If the battery is good, then there is likely something wrong with the alternator. Dim Lights: If you notice your headlights or other lights dimming or flickering, this can indicate that they aren’t getting enough current.
How to tell if alternator is bad?
How to Tell If an Alternator is Bad 1 Dead Battery: Your car battery will die without a working alternator to keep it charged. If your battery dies, you should test the battery (free at AutoZone). If the battery is good, then there is likely something wrong with the alternator. 2 Dim Lights: If you notice your headlights or other lights dimming or flickering, this can indicate that they aren’t getting enough current. Generally, the dimness will worsen as the alternator wears. 3 Warning Light: Most cars are equipped with what is otherwise known as the battery light. This light often has a misconception that it means the battery is bad. What it actually means is that the alternator is not properly charging the battery. 4 Sluggish Accessories: Another possible sign is if electrical accessories or features like power windows move more slowly than they typically do.
Why does my car battery die?
Because the alternator supplies current to the vehicle’s electrical systems, this is where you’ll notice most that something is amiss. Dead Battery: Your car battery will die without a working alternator to keep it charged. If your battery dies, you should test the battery (free at AutoZone). If the battery is good, then there is likely something ...
How many volts should a car battery be?
Place the multimeter probes on the battery terminals. With the car running, you should be seeing somewhere between 13.25 to 15 volts with a fully charged battery. If you are not, and you are only seeing battery standing voltage (around 12.2-12.5) then your alternator is still not properly charging.
Where is the alternator mounted?
The alternator is mounted to the engine, either the front or the side depending on the vehicle. If the alternator must be accessed from underneath the vehicle, a hydraulic jack, jack stands, and wheel chocks will be needed to lift the vehicle and maintain a safe work environment.
Can you put a belt on a pulley?
Due to tight clearances between the pulleys, it is usually best to place the belt onto the pulley (s) that have ‘a lip' (usually the grooved type) and slip the belt onto the final pulley without a ‘lip' (usually the smooth type).
Can a weak battery cause premature failure of an alternator?
Now is a good time to clean, inspect, and test the battery. A weak or failing battery can cause premature failure of the replacement alternator. If you're not sure how to test it, bring it to AutoZone for a free test.
Step 1: Before You Start, Purchase the Right Kit for Your Alternator
The assumption is that you have already purchased a brush and regulator replacement kit for the model of alternator you have before starting this instructable.
Step 2: Safety First, Disconnect the Car Battery
Disconnect the +ve from the battery for safety, I actually did not do this and bumped a +ve wire connected on the Alternator which created some brief fireworks, so my advice is to disconnect the +ve on the car battery first.
Step 3: Remove the Alternator
Take some photos of the alternator in position and the orientation of the wire harness, ie the wiring socket at the rear of the alternator. Before unbolting the alternator ensure you unclip the wire harness on the rear of the alternator.
Step 4: Remove the Rear Cover on the Alternator
Now you have removed the alternator, remove the plastic cover on the rear of the alternator, typically there are two bolts to be removed to remove the cover.
Step 5: Remove Old Regulator and Brushes, Fit New Kit
With the rear cover on alternator removed, take some photos of the regulator, and wiring to and from the regulator and the brushes. These maybe handy should you have issues refitting the wiring.
Step 7: Refit the Alternator
Refit the alternator back into your vehicle and make sure the fan belt is tight.
Step 8: Now Run Some Tests to See If You Have Fixed It
Attach your multi-meter +ve to car battery +ve and multi-meter –ve to car battery –ve, set the multi-meter voltage range to 20VDC or the next above whichever is available on your multi-meter.
How much does it cost to fix an alternator?
How much do alternator repairs cost? It depends if a repair is possible. If not, you’ll have to have it replaced, which can run between $500 to $1,000 (including parts and labor). Otherwise, for something simple like replacing an alternator belt, expect to pay about $100-$150 (not including diagnosis).
How does an alternator work?
How An Alternator Works. Simply put, an alternator converts mechanical energy, which is made by your engine, into electrical energy. Components like your AC, power steering, power windows, and radio, can’t run on mechanical energy. Instead, they need electricity, which is why the alternator is so crucial.
Why does my alternator make a whining sound?
As stated previously, your alternator runs off a belt that’s connected to the crankshaft. If you begin to notice a whining or growling sound coming from under the hood, it signals there might be an issue with the system. These include a damaged or misaligned belt or worn bearings.
Why is an alternator important?
Instead, they need electricity, which is why the alternator is so crucial. You might think your battery handles this, but in truth, it’s only in charge of getting your car started in the first place. This means that the battery starts the engine, and the alternator keeps it going.
What does 12.2 mean on a car battery?
12.6V is the magic number, it should not drop far below this range. Anything below 12.2 means your battery is only half-charged. If it is far above, then there is a problem that may lead to a blown alternator or battery. If it is low, unhook the battery from the car and attach it to a charger.
What is a voltage regulator?
Voltage Regulator. You can think of the voltage regulator as basically a surge protector for the alternator, controlling the amount of power it creates. If there’s too much electricity being sent, it can damage the different components. Yet, if there’s not enough, they won’t be able to operate.
Does a new alternator come with a warranty?
Obviously, a new alternator will cost the most, but it is sure to last the longest. Thankfully, either a new one or a refurbished one should come with a warranty.
How to repair an alternator?
There are essentially three ways to make an alternator repair (either by the mechanic or yourself): Replacing the old alternator with a brand new one. Replacing the old alternator with a used or refurbished one. Refurbishing (repairing) your old alternator. More on this topic and how to make a proper choice lower in the article.
How long does an alternator last?
A refurbished or repaired alternator (if the repair is done in quality) should last at least 100.000 kilometers without any problems. Almost all parts can be bought separately and are meant to be replaced. The only limiting factor for this solution is the build of the alternator itself.
Why does my alternator snap?
10. Snapped or damaged serpentine belt. In case of an alternator repair, serpentine belts can snap or get damaged for two reasons: either its worn out or the alternator pulley is jammed. The snapping can happen at a moments notice or a screeching sound may previously appear.
Why does my engine make a screeching noise?
Main reasons for this can be: Front bearing is worn out which means the rotor gets stuck and the serpentine belt slides over the pulley.
What does it mean when an alternator makes a grinding noise?
4. Grinding noise from the alternator. When a grinding noise appears it is almost certain that the bearings have worn out. There are two bearings, one in the front housing and one in the rear; these bearings hold the rotor in center.
Where is the alternator located on a car?
Here the biggest problem could be accessibility to the alternator itself. On most cars the alternator is located in the upper part of the engine, in a visible and easy-to-reach part of the engine bay.
Should I buy a refurbished alternator?
Buying a refurbished one is the next best thing to a new alternator. For this option, do it if the price is significantly lower than the cost of a new one. Just have in mind the longevity of repair as a refurbished or worse, used one, probably won’t last as long as a new alternator.
Step 1: Disconnect the Battery
First and most importantly: disconnect the battery. There may be several wires or just one wire on your alternator, but rest assured that one of them is hot. If you don't disconnect the battery, you're very likely to end up grounding a live wire during the process.
Step 2: Disconnect the Wires
Now that the battery is out of the way disconnect the wire or wires from the back of the alternator. This is usually a very simple process but if you're unsure as to where they go, label them as you take them loose.
Step 3: Remove the Belt From the Pulley
Every project has a tough spot, and this is the tough spot for alternator replacement: remove the belt from the pulley. Somewhere on your vehicle there is a tensioner pulley. You'll need to move it enough to slip the belt off the pulley. Our '95 GMC has a standard spring-loaded GM tensioner that required us to pull it back with a wrench.
Step 4: Remove Bolts
Once the belt is off just remove whatever bolts connect the alternator to the bracket and you're good to go. Our model required the removal of three bolts: one at the front and two at the rear.
Step 5: Halfway There
With the old alternator in your hand you're half way home. You'll likely find getting the new one back in goes much faster since you already know what size the bolt heads are and where everything is.
Step 6: Examine the Replacement
Examine the replacement unit before reassembly and make sure it will work for your application. Our replacement was a junkyard find so it is great deal dirtier however it has the advantage of actually working -- a significant improvement over our previous busted unit.
Step 7: Reverse the Removal Steps
To complete the project just reverse the removal steps paying careful attention to belt routing and tensioning. Hell, even if you bought the set of Cross Force wrenches for the job you'd still be hundreds ahead of the cost of what a shop would charge -- and you get some new tools out of it. We can think of far worse outcomes. Cross Force Wrenches
What does an alternator do?
The alternator plays a vital role in supplying power to the car’s AC, recharging the battery and ignition. When your alternator is faulty, the battery power is drained fast, and you will find yourself with a stalled car. But what can cause the alternator to go bad? Table of Contents.
How to check alternator charge?
Diagnosing an alternator that won’t charge 1 Tap the alternator carefully with a hammer while the engine is running; if the charging goes back to normal, the carbon brushes inside it are worn out and need a replacement. 2 Check the large power cable to the alternator and the fuse, usually, a large 40-60 amp fuse near the battery. 3 Check the ground cable between the engine and the body. 4 Check the serpentine belt and make sure the alternator is spinning with the engine. 5 Check the small power supply wire and the charging light wire. You can measure it with a multimeter, but you might need a wiring diagram and some car electronic skills to do this correctly. 6 You can measure the diode assembly and the voltage regulator to make sure they are not damaged. You can replace these with some alternators, but it is often the same price to buy a new alternator nowadays. It is up to you what you think is more worth it.
Why is my alternator not working?
Sometimes there is an electrical problem in the alternator, and even if the voltage does not change, it might be damaged. Another common cause is a bad diode plate or a voltage regulator. You might need some knowledge about alternators to replace these in most cases.
How many wires does an alternator have?
An alternator does usually has 3 or 4 wires to it to function properly. You will find one big main cable together with two or three small ones. All these wires are important for the alternator’s function, and if one breaks off – you might lose the charging function.
What happens when the serpentine belt fails?
The serpentine belt powers the alternator, and if it fails, the alternator will stop working the moment your belt wears out and breaks, or the pulley becomes damaged. This can also happen if the serpentine belt ...
Why is my car not charging?
The most common reason why your car is not charging is actually because of a worn-out or damaged alternator. You can carefully tap it with a hammer while the car engine is running while checking it with a multimeter on the car battery to see if the voltage is changing. If the voltage change and go back to normal when you tap it lightly ...
Is it worth replacing an alternator?
It was more common to replace parts inside the alternator like the carbon brushes, diode plate, or voltage regulator on older cars. Nowadays, alternators are quite cheap, and mostly it is more worth to replace the whole alternator.
