Motorcycle Charging System: Bad Regulator/Rectifier 

It’s like doing an apprenticeship watching these vids. Awesome, really appreciate the content.

Thanks for the video! I'm pretty sure this is the problem with my bike. It's throwing an "over voltage" code. This is the only video I've seen so far that shows over voltage. Thanks again!

This guy's a. Damn good bike mechanic and great explanation ... Good job

Very concise and easy to understand explanation.Been riding,building and restoring bikes for over 40 years but elecrical stuff is still witchcraft.

Since, I lost a battery due to a bad rectifier-regulator. I can say this for sure, thanks to you sir.

Great video!!! just an observation the shock mount bushing is gone and looks like its digging into the aluminum housing.

Outstanding job mate. Love this mech stuff on cars and bikes. One more weapon to my arsenal 👍😊

Hi, I have a strange problem on my Magna. Short version of the back story. Instead of removing crabs and cleaning after sitting I dumped carb cleaner in the tanks and carbs until it finally sprung to life. A few times the "Starter seemed to stick." Then after she was running great. I was about to change the oil, and wham, she went lights out. I have a new battery. checked every fuse and ground connection I can think of. Easter egging a starter, ignition switch, start button is more than the bike would be worth whole. I have not electric what so ever after hitting the button.

Thank mate let me use this knowledge on my Harley now 🛠🛠😅

Super helpful! Thanks for taking the time to put this video out!

Great video - thanks for posting. Well explained info , much appreciated. I was hoping to see the result of the rect/regulator replacement....did it solve the problem...? Thanks.

Another great video. I have linked a few of your videos to the shadow groups on Facebook. It's also helped me out on my 99 vt750cd. Thanks for the great videos keep it up.

Most helpful tip. Thanks very much

Thank you sir.. my bike started with a problem recently, where i was riding, and my eletrical went out but the bike was still on and the headlights were still on but the dash,accessories, tail & turn signals went out. when i tested the battery with bike running, the voltage was running well into 17v. So i'm assuming the regulator went out.

Thank You For This. Excellent Videos

Brilliant video thank u 😍👀👀👀👀👀😀😀😀😀👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍

Nice video very educational, Thank you, I do have a question though, I have a 2019 can-am Ryker Rally, I put LED headlights on it, I have a sound bar and a LED light bar, a camera system and the multi-color light pods, I am planning on putting a nice music system on it, what can I do to make sure I still have the power to operate all this stuff, with my current set up, I am losing the charge, I put it on the battery minder it gets full charge, but if I turn it on for like 2 minutes and put the minder back on the voltage is down again, so with this now I get a VSS FAULT, and eventually it will go into limp mode but once its shut off the bike resets and cranks like normal, but I lose a lot of safety features.

My 2006 vulcan Nomad at "idol" shows 14.6 volts. Then at high rpm it does not rise, stays at 14.6 volts. Is that the stater or reg/rectifier. I Have an intermittent mis at idol ? Thanks.

Hello sir. I checked the charging system and according to the specifications everything is fine. After a few kilometers the motorcycle shows an error and fails to start. I replaced a generator and a regular meter

My zx10r at 5k rpm its 14.7 volt but when I released the throttle to idle the voltage just keep trickling down. It seem like the charging voltage at 5krpm is normal but when it sit at idle the voltage keep dropping. Idling should be a little over 13 volt.

How quickly does overcharging kill a battery? My 2015 Kawasaki KLR 650 seems to be HARD on batteries. I got stuck last year when my battery died on me while I was out riding. I decided to try a Duracell Ultra AGM battery (2-year warranty) from Batteries Plus. I put it in last year on July 27, 2018. I was concerned with how the KLR had been starting lately, so I decided to take the battery in to Batteries Plus and have it checked out. The guy told me it needed to be replaced. Luckily, it was under warranty and he gave me a new battery. He said this is a top of the line battery and should get anywhere from 3 to 5 years of life. I got 13 months.

I'm hooked up a phone charger to the fuse on my bike it's a Kawasaki zx636 one wire burnt in the stator one wire burnt in the rectifier and one wire burnt in the fuel pump I replace most components but it won't turn the starter what should I look for next please answer ASAP because I have no more transportation

Hey I have a Shadow 750 that I just bought. The previous owner replaced the rectifier/regulator last year. Today I went for a ride, parked the bike and then I couldn't start it. Battery was completely dead. I got the bike home and charged the battery. I started the bike, and tested with the voltmeter and it reads 12.5V at most. When I rev the bike, it increases very little to 12.6/12.7 and then it starts droppping. I can't get it to go past 13v. Should I suspect the stator at this point?

Thanks much

I got a yamaha v star 1100. 2002 I put a new speed sensor on it still not working can you help me out I am Johnny jeffers

What if i put revolution on my engine and the voltages goes down?thanks

Thanks for this lesson 👍. And the time and effort you put in!

I really appreciate this one. This is a simple tip to diagnose this part of the charging system. Years ago I went through a charging issue and would have loved to have had this info. Thanks as always. Great Video!

Cody I use to be a auto technician and couldn't agree more with you. Very knowledgeable about teaching people the basics in a practical way.

Cheers for your video. I think my reg rect is dead as I have voltage AC voltage going in , but no DC voltage coming out. Thanks.

The Honda Shadows come from the factory with shitty regulators. They do not work very well and send excess juice to ground when the battery is charged, which makes them run very hot and also eventually will burnout your stator also. Before all this happens, you should first: cut out the connector plug between the stator and the regulator and solder the wires together. That's one of the weak spots in the system. They usually make a poor connection, heat up and melt. So do that first. Then replace your voltage regulator with a Mosfet regulator (One from Ricks or another brand, anything that uses Mosfet technology. Those are the main reasons why the stator burns out. It's working over time to keep the battery changed and burning out prematurely. The Mosfet regulators run a lot cooler and send more power to the battery, even at idle, which the stock regulators cannot do. If you run any added accessories on your bike, you sill start to have electrical problems because of how the system is designed. They're just not good enough to keep up.

so quick question I have a 99 gsxr 750 got a new battery on there was good. I can start it ride it doesn't cut off while im riding im good but if I stall out or so for some reason try to start it up back the battery is dead cranks slow. sometimes it will start sometimes no. so I used a mulimeter without the bike running I got 12.3v when I start it I get 13.2v. ok now if I give it throttle it will drop from 13.2 to 12.2 or 11.8 at idle go back to 13.2 v is that the rectifier or the stator

Thanks for uploading another great video Cody; I really appreciate what you do for the motorcycling community 🙏🏻 You’ve saved me a small fortune, and it’s made me bond more with my bike. Take care

Hi Only just found you channel Great vid clear and concise diagnosis. Now let me guess after having never worked on a harley I recon they use permanent magnet alternators As do so many other manufacturers. Fortunately my old gpz900r uses a conventional car style alternator. I have noticed that quite a few bikes seem to have rectifier/regulator problems and the vast majority seem to use permanent magnet alternators. Just think how many cars and trucks are on the road and how few alternator regulator problems they have, why do you think that bike manufacturers use these alternators instead of a mor conventional style

It would be best to check charging system at a higher rpm than idle, reason, the break even speed is generally above idle on most makes , unless it is 3 phase. Break even speed is the RPM needed to replenish the draw of normal engine components when running, coil, lighting etc. It is just good practice, covers all types of charging systems. Great video, and will help those in need, thanks.

Very informative video, you explain the fundamentals in a way that is easy to follow. Excellent delivery of knowledge.

This is awesome, very helpful for an electroidiot like me. Keep up the great work!

thanks for this one ,my buddy's bike has been having this problem and all his biker buddy's were clueless.

Thanks great be of advice 👍 will help me check my vfr overcharge..

I get and overcharging reading as the video shows. But the electrical check of regulator say it is ok. It is possibile?

Hey Cody, if my headlight and neutral light is dimming as it revs up, does that point to anything specific in the charging system?

Cody, thank you for ALL your instructional videos on the motorcycle charging system, stator, regulator/rectifier, & battery. Simple, to the point, and easy to understand. They have helped me understand & diagnose my system on my 2003 Honda VFR800.

dude this is saturday morning bacon! Great stuff!

Am I the only one that can't see the results!?

Great video! I learned a lot, I'm new to bikes and my kawasaki zx10r died while riding the other day D: hopefully these simple tests will save me time and money instead of attacking the stator first

Hey man, I just bought a new battery for my Honda shadow 2001, the initial voltage for the battery was 12.75, when I turn on the motorcycle and stays in idle the voltage is 12.45/.51, when I accelerate the bike the voltage jumps to 14.5, this is the second battery that I bought in one year, my question is, are this the normal numbers?

Love the slogan “Pretty Rippin” lol. Let me use it in a sentence...”officer I was not speeding, the sound is pretty rippin! “ love that line. Lmao. Great video too bro

much appreciated..very helpful ...I will be checking mine. Like the last sentence about if 5000, 6000 8000rpm and only getting 13,5v then look at stator..so in one lesson I learnt about regulator and stator . thanks

awesome video !

Thank you Cody,I've had a few small battery problems in the past week, I took my battery to the shop & all is well up to now,but,I'm yet to put gas in my Honda cbr1000 & actually run,I ran out of gas last week,take care friend & thank you for your Valuable information,Time & Excellent battery & charging video 🙂🙂🙂

Is it possible to have a Regulator/Rectifier that works/Fails intermittently ?? I have an Indian FTR which needs a new battery every few months. It always Cold starts fine, when i check the stator it gives 34 vac when cold at 2k rpm like the manual says on all phases, and the regulator maintains a nice 14.5 vdc at all rpms. Yet the bike dies while running and leaves me stranded, installing a new battery solves it, and testing the previous battery, after putting it on a tender/minder, it wont hold over 10 volts

So today I took a ride on the highway my engine and batt light went on....I watched my voltage meter head south to below 5v...luckily I made home. Turned it off and tried to start again, would not turn over,, just clicked rapidly....Pulled my seat and checked the batt showed 11v....any help is appreciated

Will the rectifier regulator also cause the battery to not in my case rise up to 14.5v when at rpm is at 5k. The battery voltage doesn’t drop but it doesn’t raise either and I have to jump it when I stop

Hello sir..my ninja 400r charging system is acting funny..mechanic says battery is OK and looks problem in rectifier or magnetic coil or both. Can u guide me since you have so much experience..my bike won't start after a ride on a full charge battery and make computer electronic type sound while I start it after off. I have the video of this issue and can show you..let me know..thanks

Thank you man that's exactly what I needed to know rectifiers the problem👍

I’m about to order a new RR for my ‘90 Africa Twin. Saw over 17 at 4 grand. Boiled the las battery

This video will help me with my 1985 Honda Shadow VT1100. Thank you.

Thanks for the video. I have a Suzuki Burgman 650. Just replaced the battery. At idle I am seeing around 14.5 V. At 3000 rpm it drops to about 14.2V. Should I be concerned?

Your explanation was so easy to follow. I will be tackling my system tomorrow and thanks to you, hopefully sorting out my motorcycle issue!

Great video. I will check my readings. In the meantime, my bike had new battery but I didn't ride for 2 years. Now I have to connect battery to charger. It charges battery so bike can start no problem. I can ride the whole day. I can stop bike many times and bike start again. Next I go home, I don't connect battery to the charger and I leave bike overnight. Next day bike doesn't start 🙁. I have to connect charger again. What do you think is the problem?

Informative vid.........shock absorber bushing looks like it's blown out.

My 07 sportster 1200 had a check engine and battery light come on. The battery died so I replaced that. Within a few minutes the lights came back on. I checked the battery while at idle and while RPMs around 5k, voltage would be around 12.4 and then randomly drop to 2v, 5v etc and then back to 12.4. I swapped the voltage regulator and tested, voltage goes up to 14v at 5k RPM but then flashes 7v and other random numbers, then back to 13.5v, 14v. What’s the deal with that?

On mine is showing 13.6 staying there or so with high beam. Soon as mines gets hot it doesn't want to turn on..acts like a dying battery..battery is brand new. If bike is just warm or cold starts easy. But hot it won't. What can it be?

The rectifier/regulator voltage control is subject to prevailing ambient temperatures in which the bike operates. Generally the regulated voltage in lower ambient temps. (< 50F) is higher ~14.75v, whereas in higher ambient temps. (>80F) the voltage is reduced ~13.5v to reduce stress on the battery (over charging/cooking the battery). This is all done by electronic thermal sensor (thermistor) in the rectifier/regulator to "trim/modulate" voltage to a safe level. I should think 15v is too much applied to the battery & cycle system.

Nice video Cody!

So, Question......My 1981 KZ 550 is putting out right at 16.5 when i increase RPMs to 4000 with high beam on. Thats still too much, Correct? I had a melted stator plug just as you showed but have repaired all that. REG REC? did a diode test on it but it checked ok

Cody I could not keep a charge in my factory supplied battery so I did what anyone would do and bought a new agm battery...and hooked it up....and my rectifier smoked ...then literally popped......battery reads 13.4 ...bike is an apollo rx250...

HELP! Daily driver down : Hondacb125s 1982 - runs great with no lights... horn weaky.. /add new battery back in= wont crank! whats my problem please?

I have a 2006 Yamaha R1 that is no longer charging the battery. I have already replaced the stator and regulator rectifier. The battery tests over 13V at aprox. 60 degrees F. The connections to the regulator seem to test fine, I've checked the 50A fuse and it seems fine. I'm wondering if it could be the wiring harness or the flywheel itself. Any suggestions would be much appreciated.

When I switch my bike on my speedo registers 105mph. The battery I just replaced was on 19v so was overcharging.. now with a new speedometer, clocks and battery my speedo still registering 105mph when bike turned on and not moving. Could this be the rectifier? Thanks

I have a KTM Duke 390 i changed the stator and i bought a new battery. But after a 30min ride if i switch the bike off and then try to start it the battery is barely alive and it wont start. I have a voltage meter on the dash and it shows 11.1 Volts. After letting it sit for 10min the bike starts and the screen shows 13.7/14.3V and in the middle of the ride it starts to drop to 12.4V and when i rev it past 7k rpm it goes up to 14.3V and starts charging again. The only thing i can think of its the voltage regulator but i am not sure. Should i just buy a voltage regulator or could there be a different problem?

Great videos thank you My issue is on 1980 Honda CB650. Bike not charging swapped out stator rotor and rectifier. Reading on 3 leads from rectifier .5. Diodes read good and directions tests on rectifier read good. Stator unplugged and running reads good and increases with throttle. Can there be an issue from rectifier to battery other than wiring? Everything else on bike works no other issues. Puzzled???

Hi TMMD guy, I am from India. My scooter has 12v 5a battery, when I went to replace dead battery the battery dealer said my scooter regulator giving up to 15 v to battery which is bad to battery and it should give between 12.5 to 14.5 and told me to replace the regulator. Since you said it’s ok until 15.5v can I skip replacing regulator ?

To accurately test a battery, it MUST BE LOAD TESTED! The way that you show testing it only shows the surface charge and not the amperage load that the battery is capable of producing! I have tested many, many batteries that would show 12.4 - 12.6 or higher and when you load test the battery it fails the test miserably! I am surprised that the manual says 15.5, most automotive alternators typically limit it to 14.2 volts to avoid overcharging. Normally when a regulator fails and allows too much voltage to go through it usually cooks the battery and you will find that the electrolyte is low and has boiled out of it.

Hi. First off all I want to thank you for the detailed information that you have shared with us. I have finally found the problem on my honda shadow. I need to ask you a suggestion. I ordered the new voltage regulator, but unfortunately it needs 2 weeks delivery time. My question is can I run the motorcycle with 18volts charging for 45min and then switch off the charging current for about 30 minutes and then reconnect. I mean can I do manually that the broken part on rectifier does automatically?

Hello good Morning. I would like to be able to ask you a question about a 2011 yamaha bulcan review it and I have changed 4 fuel pumps and I always lose reaction when accelerating after I have 30 minutes or less. cold works well. But afterwards he no longer responds when asserting. I have been from workshop to workshop for two years and no one finds the defect. I'm from houston texas and no one here has been able to help me. your experience. which may be ???? I have already changed the injectors. The coil 4 fuel pumps, pressure regulator plugs

I had to just replace my rectifier/regulator in my 1982 CM450. It was overcharging, and killed a battery, so it does happen. I upgraded to a Standegen or some such.

I’m looking into buying a 2006 Honda rebel 250 for $500 Here are the specs from what the guy told me: -new battery -new ignition -new locking gas cap -new risers and bars -rinsed the gas tank. New gas in it -clutch shifts well -oil is still good For some reason the ignition is shorting the fuse. What can cause this issue and what should I look into fixing

I have a 2002 Shadow Sabre. It's for sure got some sort of an electrical issue. Last ride I stopped at a store and it wouldn't start when I came back out. Did the old push start and got back on the road. a few miles later it cut out and sounded like it was running on 1 cylinder. No Power. Limped it along for a couple miles. (not a safe spot to stop) Got it home on a trailer. Battery is very low, and I checked the common issue connector from the stator to reg/rec. All good. As soon as this battery charges back up I'm going to do the test you showed in this video. Other than that any advice?

This video is so helpful. Helped me diagnose what was wrong with my charging system. Btw do you know where Dave is?

Man, I really appreciate these videos! This was an excellent explanation of how this charging system works, as well as the risks and safety hazards. Subscribed!!!

Just put a brand new stat. Reg.rec. on my gixxer 750. After 3 weeks I'm getting 13.4 at 6k. But if it weren't enough charge wouldn't my bike lose power? Keeping in mind I run the fk out of it frequently.

I really fw your videos! I really appreciate the fact you're a Honda mechanic too. On Friday I'm going up north to the cabin where my new to me 1994 300ex (seen you had one too) to try and diagnose her selective starting issue.. lol

Rly nice video! I have a similar problem. Its Burns battery after battery. Last battery was totaly dead. Put a new in and the bike wanted to die already after around 100km But! Its starts out around 13, when i rev it goes up to about 15. But then it stays there. Even when i let it idle it stays on 15 until i restart the mc. Is this overcharging? Ty!

hey dude ive finally got a honda - been following you a while its a 2000 VTR1000 and my bike wont charge- ive changed the solenoid, stator, battery and im gonna try an OEM RR but have tried another RR it also has a ground to battery outside the plug does that matter?- anything else I can try?

Hi! I would love if you could answer a question! Why is the rectifier only outputting 9V to the headlight? It should be at 12v. The battery gets 14.3v. Is it the ret or could it be the stator?

I did everything you said to check. I have a 750 shadow. Stator was bad and I put new one. Rectifier is 14.5 v at 5000 rpm at battery. My problem is I think now is that I have charged battery so many times that I think it might be bad now. It's charging but still can't get the bike to turn over but one rotation and the battery died out. Just would like your opinion on this if you don't mind. If I get to crank I can ride but can't crank back up if I cut off.

I’ve been having an issue with my 1996, 600 Honda shadow it keeps draining my new battery I bought last week today I replaced the stator and rectifier and still it drains my battery. Watching your video would it be the fly wheel

what if you start up bike stays at 12.4v, when reving it stays around 12.5-12.6, once turned off goes down to 12.2, once light turns off, goes to 12.65? is that bad?

I think you said this is pretty much the same on all or most bikes. What about a Harley Electra glide 2009, with high beam on , should it never put out roughly 15.5 volts regardless of the rpm? Also the high beam on is crucial for this test?

The best voltage for charging a regular lead acid battery is 14.0 to 14.4VDC. Otherwise, too high voltage on the battery can also be the result of the loss of the ignition wire connection on the regulator. Also, with the series type of regulator, which has diodes in the plus and thyristors in the rectification of the minus, the breakdown of the stator winding to ground generates an excessive voltage of the accumulator at high rpm.

I have a 02 Suzuki vs800gt intruder. It shut off on me while I was riding it. I had no power to lights nothing. When I put the battery charger on it. It will fire off. But the second I that the battery charger off it dies. Any help would be greatly appreciated.

yo man just wanted to hit u back with a thumb up n say much appreciate this info... I've burnt up 3 connector plugs now from stator replaced once now ...and the rectifier replaced 2 times both aftermarket...do you have any thoughts on soldering the connectors and hardwiring the 3 lines from stator to plug (the one that keeps melting) ...idk could my issue just be that resistance building in the plug, like i said above i appreciate u... good lookin out

Nice ear lobe plates. Did you know they originated with some African tribes (in Africa)? They started small for children and as the ear lobe stretched they put in larger and larger plates. When they got to adult size the ear lobe plates got to be the size of dinner plates. Quite attractive. They can be seen in old copies of National Geographic magazines. Even bare naked African women too!

Hi I’m have issues with my 1986 yamaha virago 1100 keep burning my rectifier. What do you think the problem and keep blowing my fuse

Thanks for the video! Appreciate the tips. I am testing the charging system on my DRZ400. Thanks

2006 Honda vtx 1300 c Was riding then I hit the gas, bike turned off Bike just clicks now what’s the problem ?anybody

Thks four your excellent video I have a Piaggio Zip 2T other day I drive and same one stop me and tell me my rear lights is blinking after 2 days all my lights is blown front and rear I’m surprise my fuse don’t blown also when I drive in full throttle same times is cut don’t the speed what you think is my regulator fault thank you help appreciate

I have a 2005 1200 cc Harley Davidson Sportster XL custom I've got a battery tender hooked to it I can charge the battery I've got a brand new battery about a year-and-a-half old and I plug in the battery tender from time to time but all of a sudden about a month ago the engine light was coming on I've only seen that happen once before and it was a voltage regulator if I remember correctly but now I left the the bike said and let it cool and the next day I plug in the battery tender takes 15 minutes to show that it's fully charged fire the bike up run it for about 10 minutes idling and revving it a little bit to get it good and warm I shut it off and I go to start it again and it acts like it's a dead battery and it's been doing this I don't know how long but anybody can give me an answer back sure would be helpful to me I'm not no mechanic I've been riding for 30 40 years but I've got friends up in Illinois around Chicagoland that knows things more than I do and I don't have a heck of a lot of money anybody can help me out with this I can't even afford to buy a tester I don't even know how anybody could get back to me anyways thanks

I have a 09 suzuki boulevard m90, it shut off while riding, and I have to just start it again and will will shut off,and will make a ticking sound when i try to restart,? Help please