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2012 RG Custom. Had the original voltage regulator changed out under the recall just after buying the bike. No problems for two years and 10k miles. Then, this past weekend, got check engine and battery light. Voltage gauge was showing 11 or 12. Rev'ed engine, the lights went out and the voltage jumped to 14.5 or so. Road the 40 or 50 miles home with no further issues.

I went ahead and picked up a new regulator, but tried to do some troubleshooting last night, before I installed it - mixed results.

- Testing the voltage across the battery terminals with the bike off was in spec, according to the service manual.

- Testing voltage across the battery terminals with the bike running was slightly low - 14.2 or so.

- I turned the bike off, unplugged the stator plug from the regulator to check output of the stator. When I cranked the bike, it ran like sh*t, so I just shut it back down. Is this normal?

- Confused, but still wanting to accomplish something, I went ahead and installed the new regulator. Afterwards, voltage across the battery terminals with the bike running actually dropped to 13.9 or so.

So, a few questions:

1) Does revving the engine and having the CE and Bat light go out and the volt meter return to normal mean anything?

2) Should the bike run really poorly with the stator unplugged from the regulator?

3) Any thoughts on why the output would read lower after installing the new regulator? Can I deduce anything from this?

4) Anyone have definitive numbers for a 2012 RG and a plain english guide on troubleshooting this stuff? I have the service manual and it doesn't cover it. I have found multiple postings on multiple forums, but the numbers are all over the place.

Any help will be greatly appreciated...
 

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Had a similar issue with my bike (2013). It tested fine every time I tested. Took it to the delaer as every time I rode the voltage would drop low enough that the battery light would come on. It took about 30 minutes of riding for this to happen.

Dealer says "all is fine." I told them to ride it for 30 minutes and get back to me. Stator and regulator replaced under warranty. The pins between the two were burnt according to them although I don't believe a word any dealer says as they are all full of it.

Regardless, 13000 miles since replacement and all is still fine. Knock on wood.

Drew
 

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VR's are iffy. A VR that's just starting to go out will work most of the time. Check the Stator AC volts and the battery DC volts under load, if those # are good the VR is your calperate. Your battery shouldn't drop below 10 V while trying to start the bike. The book will have the Stator #s / rpm. Use a multimeter when checking not your in dash Guage.
 

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If the battery is bad and was not charged when you unplug the stator it may cause the bike to run poorly, this is because the battery is the only thing running the bike.
16 to 23 VAC is normal at the stator pins when the bike is running at 1000 rpms and it should put out 16 to 23 VAC for every 1000 rpm.
The voltage regulator should put out 14.3 to 14.7 at 3600 rpm at 75 F degrees.
My bike only puts out 16.9 volts at the stator pins when at 1000 rpm which is on the low end of the specs and the result is 14.0 VAC at the battery. I know it is a little low and the stator in my bike is getting to the end of its life but it still charges the battery and runs everything on my bike including the audio amp and the heated gloves and jacket.
You should be fine at 14.3 VAC, load test the battery and see if it is bad, if you have the battery on a tender take it off for a few days and see if it is holding a charge.
 

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Maybe I'm missing something, but what's wrong with 14.2 at the battery with the bike running, from all of my experience that's good. I also agree with if the battery is weak, the bike will run bad. The battery may show the proper voltage, but you should load test it to see if it's actually good.
 

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Discussion Starter #7
Maybe I'm missing something, but what's wrong with 14.2 at the battery with the bike running, from all of my experience that's good. I also agree with if the battery is weak, the bike will run bad. The battery may show the proper voltage, but you should load test it to see if it's actually good.
The initial test showed 14.2. After installing a new VR, it dropped to 13.9. I installed the new VR because I was seeing check engine and battery lights and the gauge dropping to 10 or 11.

I plan to load test the battery tonight...
 

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Discussion Starter #8
If the battery is bad and was not charged when you unplug the stator it may cause the bike to run poorly,
Would the regulator not being grounded have the same effect, i.e. bike running poorly?


16 to 23 VAC is normal at the stator pins when the bike is running at 1000 rpms and it should put out 16 to 23 VAC for every 1000 rpm.
Can you tell me specifically, how to test this? I have a multimeter and I can figure out how o set it for VAC. Am I testing the stator pins at the end of the plug coming from the primary case? The end that plugs into the voltage regulator? Is it just a matter of sticking the leads into the holes in the stator plug?


The voltage regulator should put out 14.3 to 14.7 at 3600 rpm at 75 F degrees.
This is the confusing part. With the initial regulator on the bike, it was putting out 14.2. After putting the new regulator on, it is at 13.9.

Thanks for the advice and help...
 

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The last time that I had the battery light and the check engine light come on (quite a while ago), I replaced the HD garbage regulator with a Cycle Electric regulator.

I have not had an charging issue since!!!!!!
 

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Another issue however not as common on bikes is to have a couple of diodes fail (blow) in the rectifier which still show charging voltage but improper amperage this normally happens when a charging system is over worked i.e. Trying to charge a dead battery I try to explain to customers that alternators aren't battery chargers they need a good battery to operate efficiently and FYI I wouldn't panic about 13.9 to 14.7 when running


Sent from Motorcycle.com Free App
 

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Too bad Harley Voltage Regulators (VR) are not reliable, have poor quality or are just poorly designed. Come on now, Harely has been using VR's for decades and apparently can't figure out how to design one that is basically bullet proof. Or, is Harley intentionally designing the VR to fail in order to increase service revenue at their dealers.
 

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Oh another test I do is check your ripple voltage I use this ol' boy
View attachment 173546

Guessing <5% ripple (they still make that?), it's a rectifer. Diodes? are they Selenium (Se) one's? doubt it, would smell rotten eggs when bad. Seriously! think HD designs or even QCs the common VR, at least they back the black box like a check valve, unlike tesla
 

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Discussion Starter #14
Load tested the battery last night and it is fine. Still could not figure out how to consistently read AC voltage from the stator. The regulator is putting out 13.9 at idle, 14.2 at 3500 RPM. On a test ride, the gauge is reading anywhere from 13.9 to 14.5, depending upon RPMs. All this after installing a new voltage regulator.

At this point, I'm going to call it fixed and move on to my stereo install...

Thanks for the replies and suggestions. Very helpful...
 

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to check your stator you will unplug it from the regulator and check the AC voltage between the pins on the plug coming from the primary the voltages listed earlier are a good reference .
One other thing no one mentioned is that to check the charging system you should start with a good fully charged battery , at least thats what I was always told and how I have always checked .
 

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I used a aftermarket battery and paid the price after only 2 years, it just didn't live up to HD specs and IMO their charging system is a little sensitive. Good luck.

Stator specs: 16 to 20 ACv at 1,000 rpm, this number should double every 1,000 rpm. Stinky primary oil with sediment might show the need for a new stator.

Voltage regulator: there is no good way to test this item but cracks, holes, or burns on the underside could be signs of a bad VR.

HD Battery specs:
12.7v = 100% charge
12.6v = 75%
12.3v = 50%
12.0v = 25%
11.8v = 0
 

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Discussion Starter #17
to check your stator you will unplug it from the regulator and check the AC voltage between the pins on the plug coming from the primary the voltages listed earlier are a good reference .
One other thing no one mentioned is that to check the charging system you should start with a good fully charged battery , at least thats what I was always told and how I have always checked .
Thanks Eagle. I do think some of my initial readings were off because the battery did not have a full charge.

I used a aftermarket battery and paid the price after only 2 years, it just didn't live up to HD specs and IMO their charging system is a little sensitive. Good luck.

Stator specs: 16 to 20 ACv at 1,000 rpm, this number should double every 1,000 rpm. Stinky primary oil with sediment might show the need for a new stator.

Voltage regulator: there is no good way to test this item but cracks, holes, or burns on the underside could be signs of a bad VR.

HD Battery specs:
12.7v = 100% charge
12.6v = 75%
12.3v = 50%
12.0v = 25%
11.8v = 0
Still have the OEM battery and get close to the specs listed when checking it. I'm still all over the place as far as the volt meter goes while riding. I realize that it is not the most accurate gauge, so not overly concerned about it. I have a few hundred miles on the bike since putting the new VR on and no more check engine / battery lights, so plan to just ride for now and not worry about it...

Thanks to all for the assistance...
 
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