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Discussion Starter #1
Hey guys/gals,

I've been troubleshooting an apparent voltage regulator problem. During a ride I noticed my voltage meter was only reading 12vdc. Before I got home it jumped back up to 14vdc. I checked voltage at the battery with bike running and it matched the voltage meter at 14vdc. I shut the bike down, waited a while and restarted it. Voltage dropped to 12vdc. I checked voltage at the battery. It read about 12.4vdc, so it still matched the meter. That tells me the meter is accurately reflecting system voltage.

I performed stator ground and resistance tests. Stator passed both. I checked stator output at idle and at 2000 rims. AC voltage output is within specs via the service manual.

I checked milliamperes draw test and it is also within specs. Everything seemed to be pointing to a bad voltage regulator so I replaced it. After I replaced the regulator, I tested the bike. The bike ran at 14vdc for two minutes then dropped back to 12vdc. I had to rev the bike to 1700 rpm to get voltage back to 14vdc. I checked voltage both times at the battery and found the voltage meter is still reading accurately. In other words, the new regulator didn't change anything.

I am at a loss. I have not load tested the battery and it is coming up on five years since I installed it. I just have a hard time believing a failing battery could drag down a voltage regulator like that.

Has anyone run into this before? If so, what was the root cause?

Thanks!
 

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Hey guys/gals,

I've been troubleshooting an apparent voltage regulator problem. During a ride I noticed my voltage meter was only reading 12vdc. Before I got home it jumped back up to 14vdc. I checked voltage at the battery with bike running and it matched the voltage meter at 14vdc. I shut the bike down, waited a while and restarted it. Voltage dropped to 12vdc. I checked voltage at the battery. It read about 12.4vdc, so it still matched the meter. That tells me the meter is accurately reflecting system voltage.

I performed stator ground and resistance tests. Stator passed both. I checked stator output at idle and at 2000 rims. AC voltage output is within specs via the service manual.

I checked milliamperes draw test and it is also within specs. Everything seemed to be pointing to a bad voltage regulator so I replaced it. After I replaced the regulator, I tested the bike. The bike ran at 14vdc for two minutes then dropped back to 12vdc. I had to rev the bike to 1700 rpm to get voltage back to 14vdc. I checked voltage both times at the battery and found the voltage meter is still reading accurately. In other words, the new regulator didn't change anything.

I am at a loss. I have not load tested the battery and it is coming up on five years since I installed it. I just have a hard time believing a failing battery could drag down a voltage regulator like that.

Has anyone run into this before? If so, what was the root cause?

Thanks!

Yes, I had the same problem on a 2012 a couple of years back. It was very intermittent, problem was the voltage regulator.
 

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My 2013 with less than 10,000 miles is doing the very same thing. Yesterday when i started the bike it was reading a tad over 10 volts, i bumped the regulator with my dead blow hammer handle and it went up to 14 plus volts. It does this from time to time. I am going to replace it but feared what happened to you, the new one doing the same thing. I have tightened my battery cables, but that did not fix it. Let us know if you find the problem and i will do the same.
 

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I noticed this off an on last year, on my 2012. It would drop down around 10, idiot lights lit on dash, and within 5 miles it would pop back up to 14. Twice it went to 16 for almost a mile, then back to normal. Over the winter, I had the bike torn down for some repairs, and put a new 600CCA battery in the bike. Second ride this year, voltage drops to 12 and stays there. By the time I got home, bike was at 10.5 VDC. Pulled the voltage regulator, tested the stator to be operational, and ordered the Cycle Electric voltage regulator. Once installed, fired the bike up to an instant 14.4 VDC. Two more rides with NO fluctuation. Harley's regulators are not the best design, and the Cycle Electric regulator mounts up higher on the front frame tubes to get it away from the heat of the oil cooler. My $.02.

Tiny
 

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Discussion Starter #6
I had the battery load tested out of the bike and it passed just fine. I'm going to go back through the charging system tomorrow to ensure I didn't miss any loose connections then will perform static checks again.

Tiny, I replaced my VR with a "no name" brand off Amazon. I'll look into Cycle Electric voltage regulator.

Dragon, I'll keep you abreast of everything I find. Your symptoms match mine, although I did not try your form of positive motivation on my VR. I will have to give that a try if for no other reason than to see if I get the same result as you.
 

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You might look at the regulator connections. I have seen some poor contact on the pins. Clean and put di-electric grease on them. Also, check the ground straps, been a known problem also.
Sage advice. Rule of thumb I came up with years ago, was any time you can describe an issue by using electrical and WTF in the same sentence ... Check for ground issues (first..). Because when a system is forced to back feed looking for a proper ground all sorts of crazy/random shit happens.
 
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I had a similar issue on my '12 and it was the regulator. I would look at the cheap Amazon one as your suspect. I dealt with this year's ago and don't have a great memory of the exacting details, but you should be able to pull DTC's for voltage issues and you can even Ohm test the terminals on your VR and compare to a known good one. Just a couple different ideas. Good luck, this can be a shitty problem to figure out sometimes. I didn't see what year your bike was, but Harley recalled many VR's somewhere around 2011-12 model years. Many more than those were affected.
 

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Are any of you running FP3? I have read that some guys running that are having intermittent problems with the voltage with that.
 

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Hey guys/gals,

I've been troubleshooting an apparent voltage regulator problem. During a ride I noticed my voltage meter was only reading 12vdc. Before I got home it jumped back up to 14vdc. I checked voltage at the battery with bike running and it matched the voltage meter at 14vdc. I shut the bike down, waited a while and restarted it. Voltage dropped to 12vdc. I checked voltage at the battery. It read about 12.4vdc, so it still matched the meter. That tells me the meter is accurately reflecting system voltage.

I performed stator ground and resistance tests. Stator passed both. I checked stator output at idle and at 2000 rims. AC voltage output is within specs via the service manual.

I checked milliamperes draw test and it is also within specs. Everything seemed to be pointing to a bad voltage regulator so I replaced it. After I replaced the regulator, I tested the bike. The bike ran at 14vdc for two minutes then dropped back to 12vdc. I had to rev the bike to 1700 rpm to get voltage back to 14vdc. I checked voltage both times at the battery and found the voltage meter is still reading accurately. In other words, the new regulator didn't change anything.

I am at a loss. I have not load tested the battery and it is coming up on five years since I installed it. I just have a hard time believing a failing battery could drag down a voltage regulator like that.

Has anyone run into this before? If so, what was the root cause?

Thanks!
I had the same issue on my 2012 last week, every test checked OK but the voltage would drop to 12 when I stopped. I ended up putting in the SE 50Amp stater and voltage regulator.
 

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Discussion Starter #12
Thanks guys. Good advice. To answer an earlier question, I ride a 2001 FLTRSEI2. I just took it in for it's 40,000 mile maintenance and asked the dealership to look at it.

Eric
 

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Discussion Starter #13
Heard back from the dealer. One of the stator cables had rubbed through the insulation causing intermittent grounds. I decided on a cable repair rather than replacing the stator. Guess I'll find out if this was the real problem when I go pick it up!
 

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Funny I should stumble on this topic. Last ride last year and couple times this year, intermittent check engine and battery lights coming on and off. 2012 FLTRX 21k, I will keep an eye on the volt meter this weekend.
 

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Heard back from the dealer. One of the stator cables had rubbed through the insulation causing intermittent grounds. I decided on a cable repair rather than replacing the stator. Guess I'll find out if this was the real problem when I go pick it up!
Hey Joe; I had the same problem on my 2001 FLTRSEI - had the stator cables replaced and that helped. But a few miles down the road the stator went haywire... (25k miles) So, back to the drawing board... I got the Compu-Fire (40 amps) 3-phase charging system - oh happy days! :)

 

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I added a CompuFire 40amp to my Evo softail. 80k on it and still running great.
 

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Discussion Starter #17
I'm sorry it took so long to get back to this. Here is a quick recap. The dealership replaced the stator. That did absolutely nothing for the problem. That's a whole other story I don't want to get into as it will draw away from this troubleshooting saga.

After determining that a brand new stator and voltage regulator did nothing for the voltage issue, I decided to check for shorts in the system that may be dragging the voltage down. I disconnected the negative lead from the battery and installed an ammeter in series between the negative lead and negative battery terminal. With nothing turned on I'm reading only 24mA; not nearly enough to impact the voltage regulator circuit. That also jives with my battery, i.e. I'm not seeing anything drawing the battery down.

I also tested voltage at the battery with the bike on (not running) and with the bike running to see if the voltage meter is accurately reflecting voltage in the system. It does.

At this point I decided to try another voltage regulator just in case i received one bad out of the box. No change with the second voltage regulator installed.

So, in a nutshell, I'm seeing 11-12 vdc at idle and just under 14 vdc at 1800+ rpm. New stator, two new voltage regulators did not resolve the problem. Meter is accurately reflecting system voltage. No significant electrical shorts in the system.

I am officially at a loss of where to go from here.

Looking for some insight from this wonderful group of Gurus!

Thanks all!
 

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When they replaced the stator did they look at the rotor? I would hope they did since they tore into it that far.
 

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I was always told, replace the rotor & stator as a pair.
Did you check AC volts ? I'm also thinking that 11-12 is too low for an idle. How old is the battery ?
 

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Discussion Starter #20
You might look at the regulator connections. I have seen some poor contact on the pins. Clean and put di-electric grease on them. Also, check the ground straps, been a known problem also.
Smarty, where are the ground straps?
 
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