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Discussion Starter · #1 ·
Hi there.
I am almost at my wits end with my 2008 Pointy 650S.
She’s starting to show her age and mileage (53k).
I have searched high and low on here to see if anyone has had this issue, but can't find anything.

Was having charging issues that appeared out of nowhere, and while fixing the faults that were there (stator coiled burned out, R/R gone), I still have a draining battery when the lights are on (on the S model the lights are always on, so I have pulled the fuse on the low beam to keep the bike charging as I need it for commuting).

So far I have:
Replaced the stator (which had a burned out coil)
Replaced the rectifier/regulator, with a MOSFET one
Replaced the battery
Directly wired the R/R (outputting 15V, which seems a little high to me - Arctic Cat 375 400 500 | Mosfet Regulator | Moto-Electrical ) to the battery.
Removed any extraneous wiring which I had added for when I had panniers mounted (put indicators on the panniers for side visibility)
With the ignition off, pulled the fuses one by one - no current drain except the fuel circuit which activates the instruments and then drops to 0, as expected.

Essentially the issue is that with the engine running something is shorting in the headlight circuit that stops the battery charging and slowly runs the battery down, however the lights remain on. (I am yet to check if they dim or brighten with varying engine revs, because I have to work on it outside, and it’s summer).

There is no voltage drop with the ignition off, so the short circuit only occurs with the engine running/ignition on.

Voltmeter across the battery showing 12.8-12.9V until I pull either the main beam or dipped headlight circuit fuses and select high or low beam on the handlebar switchgear, effectively turning the lights off, and then the voltage rises to 14.5-15V, thus charging the battery again.

Side running lights stay on, and indicators are fine.

Any tips on trying to locate where this short circuit may be occurring, or likely spots to aim for?

I cannot easily get to the yellow connector behind the radiator, even with the tank raised and airbox removed. I can’t even get enough of a grip on it to try and wiggle it to see if that affects the voltage readings at all, or look for suspect wiring as it's so deeply buried and loomed up.

I had a quick look inside the handlebar switchgear and could not see anything obviously awry.
Continuity tests with the fuses back in and ignition off were suspect as everything showed continuity however the hi-low beam switch was positioned, but that just shows there is a grounding somewhere as the switch and wiring itself seems fine inside the switchgear.

Any thoughts or insight much appreciated.
Below is the wiring diagram with the circuits I suspect coloured in, but I could be way off the mark in my suspicions.

Rectangle Architecture Font Schematic Slope
 

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... Voltmeter across the battery showing 12.8-12.9V until I pull either the main beam or dipped headlight circuit fuses and select high or low beam on the handlebar switchgear, effectively turning the lights off, and then the voltage rises to 14.5-15V, thus charging the battery again.

Any tips on trying to locate where this short circuit may be occurring, or likely spots to aim for?
That is a good detailed description of the problem, Kye. (y) With your knowledge, you should be able to solve this pretty easily.

Make sure the charging voltage measurements are taken with the engine at 5k rpm. If measured at idle, then it is normal for voltage to be on the low side.

But if rpm is not the problem, the first step is to determine if the problem is too much load or if there is still a charging system problem causing the voltage to drop even under normal load.

To check for excess load in the headlight circuit, use your meter to measure headlight current. The SV650s has dual headlights:
Low beams are 2x 55W = 110W. Current = 110W/12v, about 9 amps.
High beams are 2x 60W = 120W. Current = 120W/12v, about 10 amps.

The easiest way to measure current is to pull the headlight fuse, put your meter in current measure mode, then touch the meter probes to the fuse socket contacts.

If the headlight current readings are normal (likely), then the problem is probably a faulty stator or R/R. I know you said those parts are new, but they could still be bad. The current measurements will tell you for sure. Good luck.
 

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Discussion Starter · #3 ·
That is a good detailed description of the problem, Kye. (y) With your knowledge, you should be able to solve this pretty easily.

Make sure the charging voltage measurements are taken with the engine at 5k rpm. If measured at idle, then it is normal for voltage to be on the low side.

But if rpm is not the problem, the first step is to determine if the problem is too much load or if there is still a charging system problem causing the voltage to drop even under normal load.

To check for excess load in the headlight circuit, use your meter to measure headlight current. The SV650s has dual headlights:
Low beams are 2x 55W = 110W. Current = 110W/12v, about 9 amps.
High beams are 2x 60W = 120W. Current = 120W/12v, about 10 amps.

The easiest way to measure current is to pull the headlight fuse, put your meter in current measure mode, then touch the meter probes to the fuse socket contacts.

If the headlight current readings are normal (likely), then the problem is probably a faulty stator or R/R. I know you said those parts are new, but they could still be bad. The current measurements will tell you for sure. Good luck.
Thanks for this, I shall measure it tomorrow.
I have a dash mounted USB charging port (nothing plugged into it) with voltmeter, which is mostly accurate, and when I flick my high beams on (as I’ve left that fuse in to have lights if I really need them all of a sudden), the voltage drop even at 5k rpms or more is near instant down to the battery voltage, as opposed to the 14.5-15V measured with the lights off at 5k rpms, so I know the charging system is good.
The fact that I’ve been riding for the last three weeks without having to charge my battery every night also confirms the charging system is working.
I shall measure the circuit’s current and see what’s what, but I doubt it’ll be too much load as neither of the 15A fuses have blown since the issue began.
What confuses me is that if there is a short, why the lights still work at all. Surely a short would effectively bypass the lights altogether.
I’m by no means an idiot, but also not completely comfortable with my understanding of electrical engineering and physics et al, and I’m clearly missing/misunderstanding something here.
Appreciate the help.
 

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... the voltage drop even at 5k rpms or more is near instant down to the battery voltage, as opposed to the 14.5-15V measured with the lights off at 5k rpms, so I know the charging system is good.
The charging system may be ok under light load (no headlights) but fail when the headlight load is connected. That would explain why the battery still charges but only when the headlights are off.

What confuses me is that if there is a short, why the lights still work at all. Surely a short would effectively bypass the lights altogether.
Right. If there were a short on the headlight circuit, the lights would not work or not work well. The headlight circuit is probably ok. The current measure test will tell.

My guess is the headlight circuit is ok. One or more stator coils may be shorted or grounded, or could be the R/R is failing under heavy load.
 

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The sheet on that RR says it can handle 30A MAX continuous.....isn't that a wee bit low? You've got 10 going just to the headlamps, all the rest of the running lights, fuel pump, ECU and occasionally the cooling fan not to mention whatever the battery is needing. Isn't the charging system on the SV's good for like 500W? That would be over 40A so maybe nothing is actually wrong other than the RR being too small for the job at hand? I don't know....just thinking out loud.
 

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That is a good point, Rob. The max output for the SV650 gen2 generator is 375W so 30A is borderline. Max current for the gen2 is 375W/14v = 27A. I don't think the rating is the problem here but it would not be a surprise if the Actic Cat R/R turns out to be the culprit.

One other thing about the Actic Cat R/R. It says if it gets too hot, instead of burning out, it simply shuts down. Hmm... It may be shutting down too early.

I don't trust any of the off-brand aftermarket R/Rs. Shindengen is the way to go. But even with Shindengen, there are knock-off imitations, so you have to be careful. If I were in the market for an R/R I would only buy a dusty used Shindengen on eBay to be sure it was original. Most Hondas use these as OEM.

No matter what the problem turns out to be, even if the Actic Cat R/R is good, I would put the stock gen2 Suzuki R/R (which has proven itself over 19 years to be bulletproof) back on this bike. Even though the gen2 R/Rs are SCR(hot), not MOSFET(cool), they are mounted up front with sufficient airflow and virtually never fail.
 

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Discussion Starter · #7 ·
That is a good detailed description of the problem, Kye. (y) With your knowledge, you should be able to solve this pretty easily.

Make sure the charging voltage measurements are taken with the engine at 5k rpm. If measured at idle, then it is normal for voltage to be on the low side.

But if rpm is not the problem, the first step is to determine if the problem is too much load or if there is still a charging system problem causing the voltage to drop even under normal load.

To check for excess load in the headlight circuit, use your meter to measure headlight current. The SV650s has dual headlights:
Low beams are 2x 55W = 110W. Current = 110W/12v, about 9 amps.
High beams are 2x 60W = 120W. Current = 120W/12v, about 10 amps.

The easiest way to measure current is to pull the headlight fuse, put your meter in current measure mode, then touch the meter probes to the fuse socket contacts.

If the headlight current readings are normal (likely), then the problem is probably a faulty stator or R/R. I know you said those parts are new, but they could still be bad. The current measurements will tell you for sure. Good luck.
So after categorically stating it wasn’t the R/R, it would appear that it is cutting off from the load required when both the headlights are on.
Dipped headlights = 7.9A
Main headlights = 8.8A.
I pulled the connector off one of the bulbs, and flicked the lights on and the voltage dropped from 13.8V to 13.4, suggesting the R/R didn’t cut out under the load of just one bulb.
Thank you to both of you; I wouldn’t have thought about the brand new R/R being a piece of crap (£140s worth of crap) and not supplying the required current, despite it being “rated” to 30A.
Guess I’ll have to spend another £100 to put it right.
Suzuki DL650 to 2007, SV650 2004 on, VL800 Volusia, SV1000 Regulator Rectifier - RR851
This is the one available from Wemoto it would seem. Can’t find the tech sheet for it on the Electrex World site; would you still look for a stock Gen2 R/R?
Can’t thank you guys enough for pointing out the now obvious place to look, that I skipped, because I didn’t revisit the R/R spec sheet and assumed it would work as advertised.
At least I can keep one light off for the time being and not worry about overcharging the battery at 15V with both lights off.
Cheers!
 

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Glad you got it figured out! (y)

btw, we've all been down the road convinced of one thing only to come to a different conclusion. Usually, I am 100% convinced my wife is WRONG! : -)

... would you still look for a stock Gen2 R/R?
Yes. Definitely. Install the stock gen2 R/R. It is solid reliable, will be plug and play, and should not be hard to find.

The recommendation in post#6 above for the Shindengen is for the gen1 SV650 only; sorry for the confusion. The stock gen2 R/R is fine, do not use anything else.
 

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Discussion Starter · #10 ·
Another option to consider would be LED H4 replacement bulbs which draw a LOT less current. The ones I'm running draw max 36W for the pair and put out 30% more light to boot. Just a thought....
Thanks for the suggestion, and I would have done it, but apparently it’s not road legal in the UK to retrofit LEDs, only if they’re OE. Annoying, but they’ll just fail the MOT, and I can’t be bothered dealing with getting stopped. 🤷‍♂️
 

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Discussion Starter · #11 ·
Glad you got it figured out! (y)

btw, we've all been down the road convinced of one thing only to come to a different conclusion. Usually, I am 100% convinced my wife is WRONG! : -)


Yes. Definitely. Install the stock gen2 R/R. It is solid reliable, will be plug and play, and should not be hard to find.

The recommendation in post#6 above for the Shindengen is for the gen1 SV650 only; sorry for the confusion. The stock gen2 R/R is fine, do not use anything else.
I’m wondering when I had the R/R replaced a few years ago, because the original did die, whether it was aftermarket or stock. I was in a flap back then because it was two days before a road trip across Europe so I needed it fixed.
I have written to the company that supplied the latest R/R, because they state it’s a suitable replacement, when it clearly isn’t, or my particular one is faulty, and see what they say. In the meantime I shall try and track down an original stock one, and hopefully I get a refund to pay for it. Until then I shall survive with one headlight, as the LED option is a no-go in the UK.

Thanks for all your help. If I could buy you all a pint, I would!
 

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I’m wondering when I had the R/R replaced a few years ago, because the original did die, whether it was aftermarket or stock.
Was the stator replaced at the same time? If so, it is possible just the stator was bad, but the shop replaced the R/R anyway without testing.

R/R failure is super rare on the gen2 SV. But the stock gen1 R/R is a completely different story; those are trash and should be replaced preemptively with a MOSFET R/R.

Thanks for all your help. If I could buy you all a pint, I would!
Cheers! 🍻
 

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One more thing. Did you test the stator AC output? Should see minimum 60VAC @5k rpm at the output of each of the three coils.

If the stator has not been tested, it is possible the R/R is working but the stator output is weak. The symptoms would be the same. In fact, the way it is failing I would suspect a bad stator before bad R/R.
 

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Discussion Starter · #14 ·
One more thing. Did you test the stator AC output? Should see minimum 60VAC @5k rpm at the output of each of the three coils.

If the stator has not been tested, it is possible the R/R is working but the stator output is weak. The symptoms would be the same. In fact, the way it is failing I would suspect a bad stator before bad R/R.
I’ve done the whole charging system; the stator had a burned out coil, I replaced it, it’s outputting [email protected] 5,000rpm, the old R/R has no continuity from one of the stator inputs to the positive output when tested in diode mode on the multimeter, so is dead, so it would seem the new R/R is cutting off/overload protecting itself at too low a current, when both headlights are connected.
I did a 35 mile ride home with just one headlight and the voltage at idle was about 13V and motorway speed (5-6000rpm) climbed to 14.5V.
If I have both headlights connected, there is seemingly no power from the R/R and the battery gradually drains, at any revs, suggesting the load is greater than it can handle, so it shuts off.

When I pulled out the dipped beam fuse, so I could have my lights off (and main beam for emergency use/filtering) the voltage would generally be 14.5-15V with the lights off and immediately drop to the battery voltage 12.8-12.9 and gradually decline again, until I turned the lights off.
 

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Discussion Starter · #15 ·
Was the stator replaced at the same time? If so, it is possible just the stator was bad, but the shop replaced the R/R anyway without testing.

R/R failure is super rare on the gen2 SV. But the stock gen1 R/R is a completely different story; those are trash and should be replaced preemptively with a MOSFET R/R.

Cheers! 🍻
I have no idea what was replaced; it was a stressful time and I just threw money at the problem. And it was about 6 years ago. Probably have the receipt somewhere in my files but I’ll be damned if I know where. 😬
 
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