How to Test an Alternator ( Testing the Voltage Regulator, Diode rectifier and Stator)

This video will cover the following
-------------------------------------------------------
How to test an alternator using multi meter
How to replace an alternator
How to diagnose alternator charging issues
Alternator ripple test
How to test a voltage regulator in an alternator
How to replace bearing in an alternator ( Alternator brush replacement )
how to test a rectifier in an alternator
How to test diodes pack in an alternator
How ecu controlled / computer controlled alternators work
How to test drive belts in a car
How to replace a decoupler pulley
Diagnosing no charge , undercharging , overcharging alternator with multimeter
How to fix a rattling alternator
How to test fuses and relays
How to test alternator duty cycle
How PWM ( pulse width modulation basics ) works
How to read waveforms
why your battery light is on
How to find a voltage drop
how to use a multimeter
How to find a overnight parasitic battery drain
How to repair an alternator and finally, Deciding on brand new vs remanufactured
Featuring - Toyota camry / aurion / corolla / daihatsu cuore / mitsubishi lancer
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[@JunkyDIYguy]

Guys, check out my latest video kzbin.info/www/bejne/i3iYZauqapuokNE

[@tattedone6753]

I have a question about my vehicle do you have a email I can message you at?

[@djeletropopstarify]

I have kind of dirty but perfectly working alternator, but it's kind of plug up with all kind of junk is there proper way to clean the alternator inside component's? and what it's proper way to do it

[@azizmakka7126]

Very helful vidios

[@azizmakka7126]

Sar. plese show me how to chek ulternet motor (capacitor) rely

[@waziraliwazirali6095]

Hi

[@davidbarlow269]

I am an electrical engineer of some 40 years experience. Your presentation is excellent. Your English is very good. Your video skills are very good. I like the use of gloves , I like your camera skills. Top marks...

[@gradyrm237]

100% the best alternator video on the internet. This cat showed me how to test everything in the circuit. Testing the pins on the connectors was a massive help. I needed to know if the PCU was sending the signal to the alternator first of all. Taking the alternator apart is out of my wheel house. I just needed to pinpoint my defective part. This homie crushed it.

[@BlackwaterDSM]

Hands down, one of the most informational and concise videos I’ve ever watched. The only way he could tell you more about an alternator is to show you how they wrap the copper up into a spool. Came here due to an overcharging alternator (first one OVERcharging in my 38 years of being a driveway mechanic) and was able to diagnose it thanks to this video. Thank you for such an awesome video!

[@lukula2934]

Could not agree more. It goes to show how many YT "experts" only know enough to be dangerous.....

[@BlackwaterDSM]

@@lukula2934 Right?! They help you out, alright…. Help you right i to the back of an Ambulance (or Hearse). 😬😬😬

[@joeblow1711]

I agree!

[@konquer247]

It's people like that makes KZbin a great source of information. Thank you for your efforts.

[@arunadevi4734]

You are Knowledge Hub. Great....

[@a.bax.5992]

I've watched quite a few DIY videos on KZbin and this is by far one of the most detailed and clear.

[@danmaryam8201]

Very educative

[@TR4zest]

I found myself pausing frequently to try to absorb all your excellent information. Wow. Thank you.

[@d.d4184]

I am a technician,and this video very good with correct information. Not sure why anyone would give you a thumbs down.

[@bobczz3919]

This is the BEST video I have seen on the charging system. I never buy a new alternator or starter. I always rebuild them for a few bucks. I will not pay 300 or more for a new alternator or starter. Thank you for such an informative video.

[@lucianoferreira613]

My car stopped while driving. Thanks to two of your videos I diagnosed a bad connection between the positive terminal of the alternator and the battery ,gosh, I'm even speaking like a pro :) , I would like to give you a thumbs up for every euro you saved me. Thanks bro!

[@andysmith7758]

This is a GREAT tutorial! Technically right on, and thorough demonstartions and explanations! You know your stuff, DIY Junky! Thank you so very much!

[@jeremyyang7234]

This is the most detailed instruction for testing alternator I have ever seen.Thanks a lot.

[@nil4309]

Definitely the best video on this! Not only explains what to test, but why - and exactly what each component should be doing. Thank you

[@yyxx5088]

your patience, dedication and keenness to detail is much appreciated

[@CarAudioInc]

the effort you put into these videos is phenomenal

[@JunkyDIYguy]

thanks buddy

[@AlimKhan-xq7mc]

Air Field lighting system how to use CCR and MCR and check the transformer

[@FranklinHicks-qs4gs]

Increase your vocabanizzle

[@RS-yj3gn]

This must be the best tutorial i have seen. Easy to follow and well illustrated. Thanks so much!

[@minaflores1018]

I just wanted to thank you for being so specific when explaining how to test and what to expect to see. This is the best video online. Trust me when I say I have watched and or read almost everything available online and not one comes close to being a thorough as you. I have been trying to figure out why my new alternator and new battery in my 2002 c320 still is not charging I found myself in an under information sh&% show. Thanks to you I have all the information needed, so that I can go back out to my car and have a good chance in figuring out my issue. Thank you so very much for your help. Keep up the amazing work. its really appreciated. :)

[@JunkyDIYguy]

thanks mina

[@Decimusblack88]

Did you figure it out?

[@andreasdrz1084]

Information in detail, no bullshit... Really good, keep it up!

[@jielsonlancenicolas5411]

That was a clear explanation on what or how the the car alternator works. I appreciate this video so much!

[@humanresource9659]

I know I'm basically repeating what another reviewer said but it popped in my head before I read their comment so I'm about to say it now: This is the most comprehensive review of an alternator I have ever seen Keep'em coming

[@robertculver3014]

Excellent. Does not waste time on simple actions. Goes deeper than many such sites.

[@habsom1406]

Superbly explained video. Clearly a very knowledgeable individual who knows his alternators and automotive electrics. Thank you for making, editing and uploading this reference quality tutorial. 😎👍

[@JunkyDIYguy]

you guys wanna see how to replace an engine??kzbin.info/www/bejne/l4qomqaait-Ihq8 or How to find a short in a modern car? kzbin.info/www/bejne/gHe3mZeYeb5_Y8U or how to tell if your car has a bad battery? kzbin.info/www/bejne/e6LaYnZ8ZtOCqpo or how about how to use a multimeter?? kzbin.info/www/bejne/npi3mKuVnZqEhc0

[@ddimitris1991]

Junky DIY guy Excellent video. One question. If in positive test between of alternator and battery the loose is up to 0.2 such as 0.7 is probably the problem with the thickness of wire?

[@JunkyDIYguy]

It could be possible to have 0.7v of a difference between the two, if you replace the cable with a larger cable than the stock cable. But if you get 0.7 with the stock cable then chances are your cable is too old and has high resistance. To make sure it is the cable, connect the multimeter to the 2 ends of the cable itself. In my experience, As long as you get around 13.5v to the battery under full load, your battery wouldn't go flat. But your alternator has to work hard a little bit. I know some people live with it, But replace if you can coz 0.7v is a significant drop.

[@gustavovidal7312]

Junky DIY guy como puedo cambiar un slip ring en un alternador

[@KenshinAE82]

Glad to see this vid. I have a question. If the alternator was charging on the cold start 13.8v and then after driving a couple of mile with accessories the voltage drops to 12.6 so definitely its not charging. Would that be a bad alternator? The truck is 15 years old.

[@anhLe-hn3ig]

Best video to explain how to debug and repair a '09 - '13 Toyota Corolla alternator I have seen. Awesome dude! Thx Your English is excellent. I just replaced my '11 Corolla alternator, so I can attest the alternator used in this video. I wish I have the confidence to repair / rebuilt my own alternator rather than paying Autozone $305 after tax for a refurbished one in Jun '24.

[@Etheo1ify]

The most detailed video on how to test, diagnose and repair an alternator. Thank you!

[@angelzlatanovski5215]

You are an awesome man. Explained everything. Thank you, thank you, thank you Sir!

[@Roudter]

I like how you measure for voltage differences between the terminals and their endpoints - eliminating connection problems. It's a good method for any older vehicle.

[@randyinchesapeake8129]

Now THIS; in my humble opinion, is what the internet was created for. To SHARE INFORMATION! (at one time called "the information superhighway") And this man did a damned good job of it!

[@HamzahVerster]

The most informative video I've ever seen on KZbin 👌🏼 Well done mate. Please continue making videos like this. I wish you all the best and good luck 🙏🏼

[@DonVTOL]

Best video on alternators I have seen yet!

[@psuitt]

I totally agree! The Junky DIY guy explains alternators perfectly.

[@royvilla5833]

Phillip Suitt I totally agree with you.

[@johnnymorris55]

An exceptional demonstration of automotive mechanical, electrical knowledge. Shared so others can learn and gain from your experience and hard work. I take my hat off to you friend. Well done.

[@hruaitea_elemel]

this is such a well made video.. exactly what i was looking for.. thank you for making amazing content

[@orleansadrianwhitakerarchb6422]

I HAVE TO SAY THIS HAS BEEN THE BEST CAR TUTORIAL I HAVE SEEN

[@wrengouws3944]

Brilliantly laid out step by step explanations and visual points! My friend I have legitimately gone through hundreds of videos here on KZbin and yours was by far thee best in this category! I'm going to be in here like swimwear and dive right into your other videos! Very well done mate!! And thank you for creating this channel!! 👌

[@JunkyDIYguy]

Thank you very much

[@Norman92151]

Very well done mate.

[@rdyam]

I've got a wide range of interests that I look up tutorials for and there's a very good chance this is the best I've ever seen - thanks!

[@niopress5162]

really appreciate the time and effort you put into making this video.your method of explanation makes it so easy to understand every detail.thank you so much.

[@nothinghere2067]

A genuinely thorough and helpful video! Thank you!

[@seanys]

This is the only alternator video I’ve found on YT that covered what I actually needed know. Well done and thank you.

[@728b]

Wow! That was quite replete. I honestly didn’t know there was that much to know about an alternator. I’m certain to watch this several times to absorb all the information. Thanks.

[@elebeu]

I especially appreciated the testing of the cables and ground for voltage drops. These are often overlooked and and multiple, small, voltage drops can add up to trouble.

[@freestyleskyline]

Amazing, clear, concise and informative. Love the video man!

[@mornebezuidenhout3003]

Best video on alternator testing yet! Exactly the information other videos don't include. Thanks

[@mikespain8655]

This guy knows his stuff. Thanks, going to test voltage tomorrow on an old tractor with possible bad alternator.

[@jessemerriman460]

Thank you for taking the time to put this together!

[@janicesmyth2183]

thank you for your great videos! I'm not a mechanic but learned quite a bit from your vids

[@mgirano5822]

A great thank you from France. You are very fast speaking but I can understand with the subtitles. Your video is quite complete and it helps me much in my problem with my Honda FR-V.

[@kareno8634]

W0W! Talk about Testing to depths I never knew existed! Thanks! . . . _now > to test my brain for efficient 'holding power'_ = )

[@claybourne7162]

Outstanding!! Thank you for taking the time to make this very detailed video!

[@PJM454]

Best DIY video I've seen on KZbin. Great job. Going to subscribe.

[@TonyPablo]

Everything you need to know about automotive charging systems, great video!!

[@damienkubik1380]

Fantastic video, thank you. Very informative and easy to follow. Well put together, and thought out. Videos like this is what make KZbin great.

[@verylittlehouseonwheels5892]

You did a good job man I'm just a guy that worked under a quad Master certified mechanic that love to teach. You hit on all of it. He made me a mechanic where most people want to be a mechanic. I never use a book only for torque specs now that I'm not a active mechanic tend to watch a KZbin page for surprises that book won't tell you the surprise once in the job

[@jacobvance429]

Your videos are very well done. Thank you for the detail.

[@nia6849]

Wow, best explanation ever straight to the point.

[@ninjaturtlegaming9890]

Wow ! I cant express how much i like the video. I highly recommend this to EVERYONE !

[@rivrevvmedia]

This is by far the best video on alternators I have seen! great job!

[@ricardoandrade7925]

You explain really good! Thank you!

[@autopilotone4]

Thank you so much for an informative video. I have a parasitic drain and have pulled every single fuse in the car and it does not make any difference. Put a voltmeter switched to AC across the battery and wow, 29 Volts AC! That looks like a bad diode in the alternator!

[@SirHoppalot]

One of the best DIY videos I've come across lately, nice job

[@luism.raposo5138]

Wow! I'm a mechanic and you my friend are very good at this. Good job. I subscribed.

[@kevinsmith8516]

Excellent video, thorough and easy to understand explanation!

[@maxxsmaxx1901]

very precise demo and lecture . Thanks !

[@sherazkhan2120]

Hats off to you my dude, your a beast by covering all angles! Much love

[@DONphantasmo]

this is one of the best alternator diagnosis videos on KZbin. Thank you!!!

[@marknaylor6550]

Very very good, best alternator class ive come across

[@ajting3090]

You are a great teacher! Thank you. No hesitation here to subscribe. All the best to you!

[@cheonglin1019]

The is the best and most comprehensive video on alternator testings and diagnosis

[@sakasmeed]

Very good presentation! So much information requires regular reviews, but its all there. Thank you!!

[@swarfmonster3998]

Great presentation, very informative. 5 star!!!

[@wbudd]

Wow, this was informative. Thank you and I'll be checking out your other videos! (:

[@JunkyDIYguy]

ha haa thanks,

[@azmyin]

Sir, this was beyond GREAT! I followed the steps for checking a faulty alternator and found out that my friend's vehicle's alternator died due to running a 5+ year old battery

[@TAQEDAR]

Thank you for your very helpful video. I know a lot about electric and electronics, but still I learned many things here about auto alternators. Thanks again!

[@Aneurysm06]

Mate, you're a legend, cheers

[@edgarsalinas6408]

good job , for sure one of the best videos outthere

[@carlosberrios2638]

Wao!!!!!!! This is like the most awesome video I have seen on youtube. The amount and quality of information it contains is invaluable. Thanks

[@richardnolan9562]

Whoever narrated this did a way better job than the f****** school I went to dude you're awesome

[@mohabatkhanmalak1161]

Thumbs up, you are very good at what you do. In my teens, around 1980, I did an auto technician course at diploma level, which has come in very useful over the years. The modern vehicles of today are so much different, especially the electrics and electronic systems and require your kind of expertise. Keep up the good work!!

[@economist633]

Where did you do that corse?

[@economist633]

Course

[@mohabatkhanmalak1161]

@@economist633 It was a correspondence course at a polytechnic in the UK. I was living in Dubai at the time around 1980. Nowadays you can get these courses much easily on line, but look for good, proper institutions. Some can be bogus.

[@CORZER0]

Wow, I remember when your channel was only 24k subs! You're gettin pretty big, congrats!

[@JunkyDIYguy]

Thanks corzero

[@peterd.1165]

Your video is very professional and brilliant - I have a 1996 Volvo 940 fitted with a Denso alternator (100/14) - some time ago it started to make a whining noise. So far, I have replaced the bearings and drive belt - The Alternator is in outwardly good condition but the Whine persists. With the engine running, the whine is stopped when the large battery lead is disconnected from the alternator and resumes when the lead is reconnected. It has been suggested to me that the noise may be coming from the rectifier.

[@intestinalworm1202]

This is a great video - well done! I used my multimeter to test an alternator out of the vehicle as per your video!

[@lasurvivor47]

Very educational. Thank you. Great video.

[@Mr.Tiger.2013]

646 dislikes jealous of this great video. Thanks for making it. One comment: I wouldn't want to risk putting the meter there while the car is starting, the surge voltage could damage it.

[@69ztang]

Feels like I was in a mechanics class. Nice video and explanation.

[@garylangley4502]

Very well done. You give good information, and your video is very professional. 2 thumbs way up from San Diego. I did not know about the decoupler. I learned about repairing cars in the early 1970's and they did not have decouplers then. A lot of my cars were so old that they did not use an alternator, but a generator instead. That BMW alternator is outrageous!!

[@JunkyDIYguy]

European car parts are expensive in many parts of the world due to the reputation as luxury cars

[@mudassirnaseem6111]

very nicely explained. i would like to add couple of things plz excuse me. while checking the rotor & stators also check their ground resistance. i.e their should be very high resistance between slip rings & its shaft, also between stator & alternator's body. thanks

[@johnswilley6764]

Thank you Sir! Informative, succinct, articulate, and knowledgeable, also well produced video; without redundancy and unnecessary chatter. You are without a doubt among the best. I am now subscribed.

[@razvandumitru2252]

The video and the information are a lot better here than some of the best youtubers explain it. Keep it up, really good job. :)

[@mohamedarshad6207]

Brillient. Spot on very useful especially the AC ripply measurement value if you get battery drain.which is missed by many. Thkyou for putting it out my friend.

[@ratboysczurek2763]

Phenomenally informative video!

[@QuanTruong7]

very informative as usual. almost 1k subs congrats in advance.. ;)

[@JunkyDIYguy]

Thanks buddy,,,

[@cesaralexisvalenciamontano7861]

Almost 1k dubs 3 years ago? And now, almost 200k! Nuts!!

[@s.mendez7160]

This was an excellent video, well produced and easy to comprehend. Thank you.

[@joamon559]

Excellent video. Logically and clearly presented. Thank you very much.

[@jimnorrison8481]

I just became an expert on automotive batteries and alternators.

[@24pionu]

MzMa

[@huanweili7699]

I learned more information on here than in my Automotive class. Lol 👍👍👍👍

[@ClappaGlappa]

Holy cow I learned so much! Excellent video! I never knew you could do individual component replacement of these but now I want to try some repairs on one I'm struggling with.

[@toddlovec3938]

Finally the best video that I can understand and covered it all thank you

[@TRCVLOGPH]

great video🚗 thank you ☺☺☺

[@fncfrancofnc]

great video bro, you just got a new subscriber

[@MrArrio45]

Very simple and clear explanations to help the DO IT Yourself people.