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This is a follow-up post/update. The short summary is that my bike is producing low voltage (12.4V at idle, 12.8V at 3K RPM). My stator passes the tests per Clymers and produces good voltage (20V idle, 56-58V at 3KRPM). My stock R/R I don't think passed, so I purchased a new one from Amazon (DB electronics, AKI6016) but I also don't think it passes Kawi spec.

I noticed the DB Electronics Regulator/Rectifier got HOT when the bike was idling. With my IR gun, I measured the temperature of the R/R to be 130F. Is that normal? The wires were warm/hot too leading from the R/R to the Junction Box.

Using the Clymers Manual (which is GREAT by the way), I probed the appropriate wire leaving the R/R to measure just 12.06V at idle, 12.6V at 2,000RPM, and 12.6V at 3,000RPM. So this issue of mine is happening prior to the Junction Box.

I believe the culprit is the new DB Electronics R/R. I bit the bullet and paid $200 for the Kawi OEM R/R via Partzilla. Let's see if this works. I'll post back with an update.

Any thoughts or feedback is appreciated. Thank you.
 

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This is a follow-up post/update. The short summary is that my bike is producing low voltage (12.4V at idle, 12.8V at 3K RPM). My stator passes the tests per Clymers and produces good voltage (20V idle, 56-58V at 3KRPM). My stock R/R I don't think passed, so I purchased a new one from Amazon (DB electronics, AKI6016) but I also don't think it passes Kawi spec.

I noticed the DB Electronics Regulator/Rectifier got HOT when the bike was idling. With my IR gun, I measured the temperature of the R/R to be 130F. Is that normal? The wires were warm/hot too leading from the R/R to the Junction Box.

Using the Clymers Manual (which is GREAT by the way), I probed the appropriate wire leaving the R/R to measure just 12.06V at idle, 12.6V at 2,000RPM, and 12.6V at 3,000RPM. So this issue of mine is happening prior to the Junction Box.

I believe the culprit is the new DB Electronics R/R. I bit the bullet and paid $200 for the Kawi OEM R/R via Partzilla. Let's see if this works. I'll post back with an update.

Any thoughts or feedback is appreciated. Thank you.
A more conclusive test would be removing the positive wire from the R/R plug, then testing the positive terminal on the R/R with that wire disconnected. By leaving it connected, you can't tell if the Junction Box is the problem or if there's just not enough voltage coming from the R/R. I suggested this test in the other thread, as I was trying to see if the Junction Box was draining the current.

Hate to say it, but for a bit less money you could've had a MOSFET R/R kit. That bypasses the JB and does away with all existing R/R wiring.

It's normal to see some heat at the R/R, since it shunts any excess current to ground. Question is, how much heat is too much? Don't think that's been studied, not that I've seen. Odd that you have low voltage and the R/R is producing heat.
 

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Discussion Starter #3
A more conclusive test would be removing the positive wire from the R/R plug, then testing the positive terminal on the R/R with that wire disconnected. By leaving it connected, you can't tell if the Junction Box is the problem or if there's just not enough voltage coming from the R/R. I suggested this test in the other thread, as I was trying to see if the Junction Box was draining the current.

Hate to say it, but for a bit less money you could've had a MOSFET R/R kit. That bypasses the JB and does away with all existing R/R wiring.

It's normal to see some heat at the R/R, since it shunts any excess current to ground. Question is, how much heat is too much? Don't think that's been studied, not that I've seen. Odd that you have low voltage and the R/R is producing heat.
Oh. I see now what you meant in that previous post of mine. I misunderstood and simply poked and prodded the postive R/R wire prior to the Junction Box. :)

So I will definitely do this test. What do you mean by "removing the positive wire from the R/R plug"? Can this one wire + plug simply be pulled out of the R/R plug with sufficient force? And thank you! You're such a wealth of knowledge and I appreciate it!
 

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Oh. I see now what you meant in that previous post of mine. I misunderstood and simply poked and prodded the postive R/R wire prior to the Junction Box. :)

So I will definitely do this test. What do you mean by "removing the positive wire from the R/R plug"? Can this one wire + plug simply be pulled out of the R/R plug with sufficient force? And thank you! You're such a wealth of knowledge and I appreciate it!
There's a lock tab on the copper spade connector inside the plug, have to look really close. Press that tab and the wire will pull right out. I use a sewing needle to press the tab, but it's possible with a small enough screwdriver.
 

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Discussion Starter #5
There's a lock tab on the copper spade connector inside the plug, have to look really close. Press that tab and the wire will pull right out. I use a sewing needle to press the tab, but it's possible with a small enough screwdriver.
This has been a tremendous help, thank you so much! Really! After some fumbling with my thick thumbs and a few YouTube videos later, I got the plug out. But I can't get my volt meter in there so I'll need to remove the R/R from the bottom of the battery box and test it that way. As for the $200 Partzilla R/R, I returned it before the order even shipped. I heard about the MOSFET R/R from my readings on this forum, but honestly just thought the procedure was way above my dumb head! But after seeing how simple it is to remove those plugs, my mind is changed. I'll continue testing things and looking into the MOSFET as a 2021 project. Be back soon for an update. ;)
 

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Wiring the mosfet is pretty easy, relocation may be the hardest part. The one I got is larger than the stock RR and wouldn't mount in the original spot.

But even relocation is fairly easy.

Just ask questions and many of us can walk you through it.

And, you're welcome, glad to help!

If you find good voltage at the positive rr terminal, then I would suspect the junction box. Some simple rewiring may be all it needs.
 

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Discussion Starter #7
Wiring the mosfet is pretty easy, relocation may be the hardest part. The one I got is larger than the stock RR and wouldn't mount in the original spot.

But even relocation is fairly easy.

Just ask questions and many of us can walk you through it.

And, you're welcome, glad to help!

If you find good voltage at the positive rr terminal, then I would suspect the junction box. Some simple rewiring may be all it needs.
I won't relocate the R/R; the previous owner put on straight pipe exhaust (which then I wrapped in black exhaust wrap). So the exhaust is far far away from the R/R. I'm researching the Shindigen SH775BA now and this seems like it bolts right into the stock R/R location.

I have a question. Let's say the R/R is spitting out some good voltage and the issue truly is the Junction Box. Will I simply wire the "B" R/R wire (white) from the R/R directly into the positive terminal of the battery? (of course with the inline 30A fuse) Anything else needed? Do I simply tape up the other end off this white "B" wire that leads to the Junction Box?
 

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I won't relocate the R/R; the previous owner put on straight pipe exhaust (which then I wrapped in black exhaust wrap). So the exhaust is far far away from the R/R. I'm researching the Shindigen SH775BA now and this seems like it bolts right into the stock R/R location.

I have a question. Let's say the R/R is spitting out some good voltage and the issue truly is the Junction Box. Will I simply wire the "B" R/R wire (white) from the R/R directly into the positive terminal of the battery? (of course with the inline 30A fuse) Anything else needed? Do I simply tape up the other end off this white "B" wire that leads to the Junction Box?
Yes, 'B' (white) directly to battery positive and terminate the other end running to the junction box.
 

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Discussion Starter #9
Yes, 'B' (white) directly to battery positive and terminate the other end running to the junction box.
I removed the R/R again (I'm getting good at this! haha) in order to test the output voltage of the R/R. I did this by grounding my volt meter and placing the red probe to the "B" R/R plug. I was reading 0.8V?!

This doesn't make sense, because when the R/R was connected to the Junction Box I was reading 12V at idle. Strange. I tried this multiple times and got the same result. My volt meter was set to DC.

Alright so next I'm going to try the "direct to battery" method, where I route this "B" plug wire directly to the (+) terminal of the battery. I just need one more thing from Autozone. I'll update here when this is done.

With the "B" wire unplugged, everything worked on the bike except for the headlight. I'm assuming once I connect the R/R directly to the battery this will initiate the launch sequence for the headlight once the bike starts?

Thanks again. One of my DIY weaknesses has ALWAYS been electronics. In fact, I didn't learn how to use a volt meter proper until a few months ago. ;)
 

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Wow, don't know what to think about that. There's practically nothing getting through the RR. All voltage seen before must have been from the battery alone. This RR must be toast.
 

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Wow, don't know what to think about that. There's practically nothing getting through the RR. All voltage seen before must have been from the battery alone. This RR must be toast.
I'll check the stock R/R to see what voltage is coming out from there. I'm looking into MOSFET now.
 

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Discussion Starter #12
I'll check the stock R/R to see what voltage is coming out from there. I'm looking into MOSFET now.
Stock R/R is churning out 13.2V @ idle, 20V @ 2,000RPM, and 22V @ 3,000RPM. A bit high, eh? I got these results with the white wire off the R/R. AKA this reading is coming straight from the R/R "B" terminal.

But then get this...when I plug in the white wire (that leads to the junction box), I see 12.7V at speed. Very peculiar. I'm ordering the MOSFET Super Kit not and I'm just going to bypass this crazy Junction Box and stock R/R. I'll also do the blue wire mod. Thank you.
 

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The traditional R/Rs use a feedback system from the B to the M wire to monitor and regulate the voltage being output on the B wire. Disconnecting one or the other will throw off your numbers, since the R/R will boost the voltage on B if it sees a low voltage on M.

Why did the voltage drop back below charging levels when B was plugged back in? That's a mystery.

Bypassing the JB here only removes a couple connectors and fuses. Everything else is bare wire. The fan relay is still connected to the circuit, just fed from a different direction. Not saying it shouldn't be done, but it triggers my WTF that there's anecdotal evidence of it helping.
 

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Discussion Starter #14
The traditional R/Rs use a feedback system from the B to the M wire to monitor and regulate the voltage being output on the B wire. Disconnecting one or the other will throw off your numbers, since the R/R will boost the voltage on B if it sees a low voltage on M.

Why did the voltage drop back below charging levels when B was plugged back in? That's a mystery.

Bypassing the JB here only removes a couple connectors and fuses. Everything else is bare wire. The fan relay is still connected to the circuit, just fed from a different direction. Not saying it shouldn't be done, but it triggers my WTF that there's anecdotal evidence of it helping.
A mystery indeed! I also heard that the JB is a place where electrons go and sometimes get lost. So there may very well be something off about my JB...with respect to only the R/R and charging voltage. Everything else runs fine. So I don't think I'll touch the JB yet. I'm using this strange charging issue as an opportunity to get the MOSFET R/R mod/upgrade done.

I hope this will get me back to nominal charging voltage because the stator passes the continuity/ground/voltage test. I posted in a previous post, but the short of is it that the 3 yellow stator plugs all yield back 0.6 (ohms, I think it is). The stator yields 20V at idle and roughly 55-56V at ~3,000 RPM. So this makes me happy at least. :)
 

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I was about to suggest checking with the brown monitor wire unhooked.

So your results point to the circuit involving the monitor wire as dragging the volts down.

The brown wire runs to the RR from the front brake light switch and the horns. So it apparently monitors system voltage from the hot side of those two items.

You might get it charging just by disconnecting the brown wire. Though I'm not sure how well it all functions without the monitor circuit. It might try to over charge. I don't see why the brown monitor couldn't be run directly to the battery with the white RR positive. If the charge voltage stayed up with this connection, the problem lies in the circuit from the brake switch and horns. If the voltage drops, the RR is the problem.

I always suggest removing circuits from the Junction Box. The headlight relay in the JB, done by the Blue Wire mod. The start relay in the JB, done by the Two Wire mod. The fan relay in the JB by installing a $5 standalone relay to run the fan.

The three relays in the JB have been found melted in problem JBs. I suspect this is what leads to the JB dropping voltage.

 

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I agree with Spockster that there are problems in general with the junction box. All of the issues he outlined should NOT be affected by hooking the white from the R/R to the junction box. But theory and practicality don't always jive! Do whatever gets the bike working.

Not sure what an over-voltage due to an unhooked monitor wire would do to the electronics. Can a 12v system run happily on 25v? higher? How much would it take to blow the CDI box? or fry a coil? or boil the battery? I have my suspicions that a bad connection from the charging system back to the monitor wire has played a part in the electrical death of some of these bikes, overtaxing already border-line relays, etc.

That's one huge advantage to the mosfet R/Rs. They're internally regulated, so they don't need the monitor wire at all.

@Spockster I think the monitor getting pulled from where it does (engineer probably thought it was good to put it on the far side of the ignition switch) was a bad idea. More distance = more points of failure. Shutting off the bike at the ignition instead of the kill switch will also immediately drop the monitor to 0, which will probably let the R/R pump out an unregulated voltage spike while the motor stops spinning. It would be interesting to sit down with the designer of some of these systems and see what they had to say about them with some hindsight to lean on.
 

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For one example, I can't imagine why the engineers thought they needed a second start relay when one has worked just fine since starters were invented.

Many of those solid state relays in the JB have been found melted. Once that starts to happen I think almost any failure is possible.

No, the white wire isn't involved with the other JB failures, but removing the white wire from the JB circuits stops the voltage drain by the JB.
 

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Discussion Starter #18
For one example, I can't imagine why the engineers thought they needed a second start relay when one has worked just fine since starters were invented.

Many of those solid state relays in the JB have been found melted. Once that starts to happen I think almost any failure is possible.

No, the white wire isn't involved with the other JB failures, but removing the white wire from the JB circuits stops the voltage drain by the JB.
It's cool just taking a back seat and read the back-and-forth between you and Thorn. You two know your stuff about these bikes! The JB is something I suspected since you mentioned it in a previous post. But regardless, I think it's a good time to just get the MOSFET R/R mod done after reading so much about it. This will allow me to bypass the dang JB, so regardless if the issue is truly my stock R/R or something with the JB it won't matter.

I researched the blue wire mod and wow...that looks easy! Especially now that I'm an expert at pulling these wires from the plugs!
 

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It's cool just taking a back seat and read the back-and-forth between you and Thorn. You two know your stuff about these bikes! The JB is something I suspected since you mentioned it in a previous post. But regardless, I think it's a good time to just get the MOSFET R/R mod done after reading so much about it. This will allow me to bypass the dang JB, so regardless if the issue is truly my stock R/R or something with the JB it won't matter.

I researched the blue wire mod and wow...that looks easy! Especially now that I'm an expert at pulling these wires from the plugs!
Yes, the Blue wire mod is the easiest mod I can think of. That headlight setup makes me think the kawi engineers had trouble with low cranking voltage right from the beginning.
 

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No matter how much I learn, Spockster will know more about these bikes than I do!

And yeah, it's like they were looking for excuses to add more relays. The headlight definitely points to known voltage issues.
 
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