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In Wiring Hell!!! Please help

6K views 36 replies 8 participants last post by  FlacoLove 
#1 ·
Ok, so I tried searching the boards for an answer and only kept digging myself a deeper hole. I am going to try and lay out everything I have done concisely so that the whole picture is clear.

1. Changed headlight to HID Xenon from Lumenez - everything worked fine
2. Changed brakelight to LED board from Moto Lume - everything worked fine

3. Installed LED Flasher Relay from Show Chrome Accessories - everything worked fine.
4. Changed front TS to LEDs from Custom Dynamics - everything worked fine
5. Changed rear TS to LED with running/brake lights from Custom Dynamics - blew a fuse after initial install, re-did all the wiring - everything worked fine.

6. Battery Died - did some testing, ruled out stator decided to change R/R to Shindeghan MOSFET--
charging DCV before change was 12.6-13.0 from idle - 6K RPM......After change was 12.7-13.5 same RPM range. This seemed strange to me so I had the battery tested and it was fine. So I figured perhaps I have a ground short somewhere. When I went to start looking for it, I noticed my headlight wasn't running. I looked up posts about that issue after the MOSFET install and noticed this

Headlight Not working after Install Thread...

I mostly paid attention to the posts by VulcanJoe and Denny as they seemed the most appropriate for me.

Post #7 seemed to be the answer, and if you read on to further posts it almost seems as though somehow my low charging voltage may have been related to this.

Post 7 reads
"i had the same problem when i installed mine so i wired it up like the factory with the stator lead to the jb then the r/r would not charge what i did was take the brown sense wire from the old r/r connector and solder it to the yellow wire from the small plug on the j/b. the headlight is on all the time now there is no longer a delay to turn on the headlight. hope this helps "

I misread this and tapped the Brown Sense wire into the yellow wire from the stator leading into the JB. Obviously, my headlight turned on (only after pushing start button), no other lights did, and in 30 seconds the main 30 amp fuse blew. I disconnected the wires I just put together to realize I just sent VAC voltage on the brown wire and it melted and shorted to the old ground wire in the no longer used R/R connector. So, I disconnected and fixed my cut. Now I am stumped, I do not see any other yellow wires coming from the JB other than the one from the stator. My headlight does not work at all, and I do not know where to attach the brown wire.

I think that this brown wire just needs to get 12V power to turn on the headlight, but I am not sure.

any help please

P.S. - I removed the White and Ground wires from the old R/R connector at the point where they join other wires because I wanted to clear up some space and get rid of the uneccessary wires.
 
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#2 ·
"i had the same problem when i installed mine so i wired it up like the factory with the stator lead to the jb then the r/r would not charge what i did was take the brown sense wire from the old r/r connector and solder it to the yellow wire from the small plug on the j/b. the headlight is on all the time now there is no longer a delay to turn on the headlight. hope this helps "
Very, VERY bad advice. As soon as the R/R turns on the FET of that phase, the FET shorts the battery. I'm afraid you have ruined your new R/R.

With the FH012AA, you leave the brown wire disconnected, just make sure it does not get shorted anywhere.
 
#3 ·
I'm not sure I fully understand your post, but I'm pretty certain you are either misunderstanding my problem, or mistaken because...
after I took everything apart and examined the wiring diagrams and wiring harness, I soldered the stator wires directly to the R/R (removing the bullet connectors), still have the 1 stator wire split and going to the JB as it was stock, and have the red wire out of the R/R going to the battery and the black going to ground. The brown wire is disconnected as it was after I initially installed the new R/R

Long story short, everything is exactly as it was after R/R installation as per instructions. Battery charges between 12.6-13.5V depending on RPM so R/R is still working, but headlight still does not work at all. Since this brown wire is tied into the headlight circuit I assume the problem lies with this wire.

All other circuits work properly, and all fuses are good.
 
#4 ·
Leave the brown wire alone. Insulate it and forget about it....
I believe most people just move the blue wire in the 8 pin connector of the JB to the empty pin next to it. (IIRC, pin 8 to 7). This solves the headlight problem.
 
#5 · (Edited)
You may already know some of this, but let me try to explain some things. The only wires that need to go to the new R/R is the stator wires and the two new wires that come with the kit for the battery. When I replaced my stator I used the original yellow wires on the bike because of the one that went to the JB. The WHT/R wire you can cut at the R/R connector and tape it off or use a heat shrink cap if you can find them, this wire is the positive lead from the R/R which you replace with a new one from the Mosfet to the battery. Your original battery wire stays in place and the Mosfet positive wire gets is added to the positive lead of the battery. The WHT/R wire being cut at the R/R doesnt matter because it is spliced elseware in the harness and is still connected to the battery. Pretty much the same thing for the BLK ground wire. The BRN wire like you mentioned is the sensing wire. IT IS NO LONGER NEEDED FOR THE MOSFET. What this wire did was take output of the R/R via the WHT/R wire through the ignition switch and feed it back to the R/R. I guess the original R/R needed to know what it was putting out. So this wire gets cut and stowed also. The yellow stator wire that goes to the JB operates the headlight relay, this is how the headlight works only when the bike is running. Basicly when you tied the yellow and the BRN wire together you took the output of the R/R 12-14 VDC and connected it to the output of the stator 50-70 VAC. OUCH !!!!! So there is a good chance you fried something. I would check continuity of the stator wires, maybe even check the output while the bike is running just to be sure your stator is good. You can find several post on how to check the stator. Hook up the Mosfet correctly. Then check the output of the mosfet, I get almost 14 VDC at idle, If the input to the mosfet is good (stator voltage) and the output is bad I would say you damaged the Mosfet. THAT IS IF YOU DIDNT FRY ANYTHING ELSE. Personally I left the headlight circuit alone, so it would operate as designed, not moving the blue wire, There will not be a headlight issue when the mosfet is installed correctly. When my headlight went out it was the only indication I had that there was a problem (bad stator). You mentioned removing the WHT/R and the BLK wires completly from the bike to where they spliced, I guess it would be ok as long as you didnt disturb the actual splice or respliced the wires after removing the unneeded ones. Hope this helps you understand whats going on. Here is a link of how I installed my mosfet.

http://www.vn750.com/forum/showthread.php?t=18361&highlight=mosfet
 
#6 ·
Ok, That's the thing. I followed your instructions to the T. The only reason I tired connecting the brown wire to the yellow wire was because my headlight wasn't working.

Also my voltage across the battery was low before I attached the brown wire also.

After putting everything back together all voltages/resistance measurments at all locations are exactly the same as they were before I connected things.

The reason I do not think I fried anything, is I don;t think I actually turned the engine over, I just hit the starter button real quick to make sure the headlight turned on. I was not running the engine. So I am not entirely sure why the wire got so hot and melted through the casing and grounded itself out..

Either way, my headlight does work when it gets power. This I am sure of, but with everything installed exactly the way you did it, the headlight does not work.

I hope this explains a little bit better why I am so confused...:confused:
 
#10 ·
Perhaps an image will help you understand what I am saying:



You connected the brown wire from the ignition switch to the yellow wire from the JB. The engine did not have to start running, just turn fast enough for the stator to output enough voltage for the R/R to trigger the FET (probably the instant you released the start button).

This created a path for the current to flow from the positive battery terminal to the negative battery terminal (the dashed red path in the image).

Since FETs keep on conducting until the current drops to zero, the current kept flowing until the main fuse blew. There is a good chance that the FET failed and shorted out. You can test with a resistance meter if any of the AC inputs of the R/R is shorted to the R/R ground wire. If you are lucky, there was enough resistance in the wires to limit the current so that only the fuse blew and no other damage was done.
 
#11 · (Edited)
So what am I looking for to see if R/R is bad. Test all 3 AC inputs to Ground output and hopefully I see infinity or OL and not a resistance reading?

Also if the R/R was bad, wouldn't I expect to see absolutely no voltage change at battery terminals with engine running? I am still seeing the exact same readings I was seeing before I created the short.
 
#12 ·
Since FETs keep on conducting until the current drops to zero..
Sorry, my bad. FETs don't conduct until zero current. Thyristors do. But then why did the fuse blow? Perhaps there are thyristors in the control circuit of the FETs..

Anyway, test the AC inputs to ground both ways (reverse the probes). If you see near zero ohms both ways then something is absolutely wrong. Also, the readings from the AC inputs to the output or ground should show about the same readings - both ways again.

If only one phase of the R/R is bad, you could still get a reduced output.
 
#13 ·
Everything seems ok.?.

Except still puzzled by the low output and headlight not working, gonna try to do some more tests tonight when I get home from work.

I chanced it and rode to work today, no problems at all on the 25 mile ride. She still runs like a champ
 
#15 ·
You stated:

"I soldered the stator wires directly to the R/R (removing the bullet connectors), still have the 1 stator wire split and going to the JB as it was stock,"

By soldering the stator wires directly to the RR; bypassing the bullets, how do you power the headlight relay needed to run the headlight? Isn't it after the bullet connectors/before the RR connector where a sole stator wire tee's off to the JB (that powers relay only when the bike is running)? You do state that you still have a stator wire going to the JB, but is it powered?; how?

Keeping in mind that you "soldered" stator directly to RR, did you also solder (tee off) one of those stator wires to the JB in order to power the headlight relay?

Also, I'm looking at the wiring diagram of the manual; that brown wire connects/branches off to a lot of things that run off DC: horns/guages/lights/switches/etc... You literally put AC current through all of this; for 30 seconds!... (something to keep in mind)... Ride safe.
I simply moved the T to a different location on the same stator wire. Yes, it still goes to the JB and def has power. (Actually what I did was cut the wires on both side near the bullet connections and soldered the ends together. I still use a connector at the R/R

Yes, I am aware of what a bonehead move I made. Still trying to figure out how I made that mistake. Bottom-Line is I have had so much success taking advice from this board that I didn't read the wiring diagram first or even trace the wires. Furthermore everytime I re-read that passage I got the info from, I still infer the same thing.

Either way, I am keeping a close watch on everything that may have been affected. To be quite honest I am completely surprised that everything is in working order. Perhaps it wasn't quite 30 seconds, it may have only been 2-5 seconds for that matter, but still long enough to do damage. I will chalk it up to good luck. Perhaps pay back on the Karma I earned by giving out some free parts to those in need. :smiley_th

So does anyone have any ideas other than moving the blue-white wire over to the empty pin location to help remedy my headlight situation.
In fact, can anyone verify that this is safe to do. Guess I learned you can never be too careful.
 
#16 ·
Ok, after re-reading the entire thread linked in th OP this is what I conclude.

I do need to connect the brown wire to the yellow wire in the JB.

BUT!!!!! First I need to disconnect that yellow wire from the one leg of the stator. Thereby bypassing the headlight relay. That is where my mistake was, and I simply read the first post by vulcanJoe wrong.

Any input here please

Also could this be a problem in the J/B not fuse related? What is going on inside the J/B? Or could this be a problem with my reserve lighting device not working properly if all the wires are connected properly?
 
#17 ·
Please tell me your not thinking about hooking up that BRN wire to the yellow wire again. You need to cap that wire tape it up and forget about it. When you turn your ignition switch on your going to apply 12 VDC from the battery on that wire. Do you have a set of schematics ? If not there is a maintenance manual you can download for free. Here is a link to the post when my headling stopped working, JD put a link there for a manual. Its a PDF file so you need acrobat reader and its about 112M. Im assuming you checked the stator output and did the resistance checks, However you did mention that you road to work and back. So it sounds like the stator is working. You could start the bike and check for the 50-70 VAC at the yellow wire on the R/R plug to make sure thats its good, Maybe you damaged the headlight relay when you hooked up 12VDC to it when you connected the yellow and BRN wires together. On my headlight post it mentions about moving the blue wire, it worked for me, then I found out I had a bad stator. After repairing the stator I moved the blue wire back to its original place.


http://www.vn750.com/forum/showthread.php?t=17610&highlight=headlight
 
#20 ·
Ok, so maybe this is obvious, but why is there a leg of the stator going into the JB anyway?

As far as I can tell, nothing at all on the bike needs AC voltage, so why the yellow wire going to there in the first place? And is there any harm to removing it? I amnot actually considering doing this, I will simply move the blue wire now, and replace the stator in the off season if it makes it till then, but I am just trying to understand the wiring on this bike
 
#21 · (Edited)
If you want to understand the wiring on this bike you need to get some schematics. It will help you get a visual picture on whats going on. The schematics are broken down by system's IE charging system, starting system ECT.... This bike is designed for the headlight to operate only when the bike is running. There is a component in the JB for this, its called the headlight relay. A relay is nothing more then a switch that is controled by something else (a voltage) In this case the relay is operated by the 50-70 VAC that the stator outputs. When the relay gets this voltage it closes the contacts thus turning on the headlight. That is basicly how it works. Thats why there is a stator wire going to the JB. If that stator wire is removed the relay will not operate and your headlight will not work. Bypassing the headlight relay will work causing the headlight to come on when the ignition switch is activated. However unless you have a voltage meter so you can see what the charging system is doing. you will have no indication of a stator problem untill your out riding and the bike dies, leaving you stranded. When my headlight went out it was the only indication that I had a problem with the stator, why my headlight relay did not get energized.
 
#22 ·
If you want to understand the wiring on this bike you need to get some schematics. It will help you get a visual picture on whats going on. The schematics are broken down by system's IE charging system, starting system ECT.... This bike is designed for the headlight to operate only when the bike is running. There is a component in the JB for this, its called the headlight relay. A relay is nothing more then a switch that is controlled by something else (a voltage) In this case the relay is operated by the 50-70 VAC that the stator outputs. When the relay gets this voltage it closes the contacts thus turning on the headlight. That is basicly how it works. Thats why there is a stator wire going to the JB. If that stator wire is removed the relay will not operate and your headlight will not work. Bypassing the headlight relay will work causing the headlight to come on when the ignition switch is activated. However unless you have a voltage meter so you can see what the charging system is doing. you will have no indication of a stator problem untill your out riding and the bike dies, leaving you stranded. When my headlight went out it was the only indication i had a problem with the stator, why my headlight relay did not get energized.
I really appreciate all your help, and I mean no disrespect, but I don't think you are listening to me. First off, I do have schematics, in fact I have them in color as well as black and white because I have three different service manuals for this bike.

Secondly I have tested the stator. I thought the stator results were iffy at best because I saw this:

Any of the three leads to ground = OL
any of the Three leads to each other = 0.5-0.7 ohm
same result with bike running is a little strange;
A-B; idle = 18VAC; 3000RPM ~40VAC; 5000RPM = 70VAC
A-C; idle = 12VAC; 3000RPM = 30VAC; 6000RPM = 50VAC
B-C; idle = 12VAC; 3000RPM = 30VAC; 6000RPM = 50VAC


I thought that perhaps leg C was slightly grounded and therefore my stator is not entirely bad, but rather it is starting to go, but when I first posted these results I was told my stator was ok. so I decided to change the R/R.

I also tested the charge across the battery with engine running before changing R/R, immediately after changing to MOSFET, and also after I created that short mentioned earlier.

Results are:

Stock: idle = 12.6VDC; 3000RPM = 12.8VDC; 6000RPM = 13.0VDC
MOSFET after install: idle = 12.6VDC; 3000RPM = 13.0VDC; 5000RPM = 13.2VDC
(this test was done with both old battery and a brand new one with same results, also had the same results after the short incident)

BUT, if I disconnect the charging leads from the battery and test the voltage across them with bike running i get 16VDC at idle.


Thirdly I understand what a relay is, I just didn't see it on the electrical diagram and was curious where that yellow wire went. In fact after reviewing the schematics again I still don't see the relay. Besides a relay can easily be powered by 12VDC so it seems strange to me that it is wired in this manner, and the wiring diagram is not specific about this matter

Furthermore, I understand your point about not knowing if the stator is bad...in my opinion I do not trust my stator, but it still appears to be working, and my battery is charging, therefore, I plan on replacing it in the winter (if it makes it) by sending it off to Tim Parrot which I mentioned in the last post I made. I will also perform TuxedoSevens case mod with the engine out so I can change out easier in the future.

The reason for my last post is this, perhaps, once I bypass the headlight relay by moving the blue/white wire I can then disconnect the stator leg to the R/R. I am guessing this line is split off of line "C" as I called them above, and perhaps by removing it I will increase the VAC across that leg, and as a result get charging results more in line with what others are seeing.
i.e. ~14VDC at idle across the battery.

If my reasoning is not sound or something sounds like it will cause damage please speak up, but please read what I have written so you do not tell me to do things, or get things I already have.
 
#23 ·
Your voltages do seem a little low..... Have you verified the meter readings?
The yellow wire that splits off the stator and goes to the JB can be removed from the JB and capped off. You will have to power the headlight some other way, like moving the headlight wire on the JB to pin 7. (IIRC)
That yellow wire goes through a diode in the JB and then to the coil of the headlight relay, also inside the JB. Once the relay is energized, it 'latches' closed and allows power to pass through the relay contacts to the headlight. If the stator is going bad the circuit may not work....also the diode or relay can go bad. Either way, the quick fix is to move the headlight on the JB to bypass the headlight relay. If you have the Clymer manual you can refer to page 340 for the JB wiring.
 
#24 ·
Your voltages do seem a little low..... Have you verified the meter readings?
The yellow wire that splits off the stator and goes to the JB can be removed from the JB and capped off. You will have to power the headlight some other way, like moving the headlight wire on the JB to pin 7. (IIRC)
That yellow wire goes through a diode in the JB and then to the coil of the headlight relay, also inside the JB. Once the relay is energized, it 'latches' closed and allows power to pass through the relay contacts to the headlight. If the stator is going bad the circuit may not work....also the diode or relay can go bad. Either way, the quick fix is to move the headlight on the JB to bypass the headlight relay. If you have the Clymer manual you can refer to page 340 for the JB wiring.
IIRC, when slim had the JB apart and was rebuilding them with easily replacable relays, he said the wiring diagrams for the JB were not 100% accurate, or maybe he said not 100% complete.
In either case, it seems Ma Kaw may not want us to know exactly how it works. :(
 
#25 · (Edited)
Yeah, my opinion is that the relay is bad.

also after reviewing some of the detailed wiring diagrams, i finally understand the yellow brown wire thing.

The way I interpret it is this. If I detach the yellow wire in the JB from the stator (removing AC voltage) and attach the brown wire to it (applying 12V DC) it should still activate the relay.

However, this is not what I did because I am slightly electrically retarded sometimes.

Anyway, I have tested the AC voltage going to the JB and it seems to be fine (~50VAC at 5K RPM) therefore I suspect that my relay is bad, and that simply moving the blue wire will solve all my problems.

Thanks everyone for all the advice/information and help.


P.S.- I also believe I could just remove the blue wire from the JB and solder it to the brown wire. :dead_hors but I think I should probably just rip that F'er out of there so it can stop tempting me to use it
 
#27 ·
Sorry about that, was just trying to answer your questions from the previous post. I guess I missed where you mentioned testing the stator also assumed you didnt have schematics because you mentioned your trying to understand the wiring. Hope you get your bike fixed and be safe. See ya
 
#28 ·
Anyway, I have tested the AC voltage going to the JB and it seems to be fine (~50VAC at 5K RPM) therefore I suspect that my relay is bad, and that simply moving the blue wire will solve all my problems.
Measured how? The voltage the JB sees in the yellow wire is pulsed DC voltage and never exceeds the charging voltage.

When you measure the stator AC voltages, you either disconnect the bullet connectors or disconnect the R/R connector. In the first case the stator is totally disconnected from the rest of the electrical system, in the latter case the only point where the stator is connected is the yellow wire to the JB. Since there is no closed circuit, no current flows in that wire and the JB sees no voltage in that wire. Actually - depending on the reverse leakage current of the diode in the JB and the insulation resistances - there could be a negative voltage, but it would have no significance.

When the stator is connected to the R/R, the R/R does not let the voltage on any of the stator legs to rise above the charging voltage. So, this pulsed DC voltage initially activates the headlight relay in the JB. As soon as the relay makes contact, it self feeds the relay coil, i.e. latches until the ignition is switched off.

When the stator is disconnected from the R/R, the headlight won't come on because, as I said before, there will be no current in the yellow wire to the JB. On the other hand, while the stator is disconnected, if you make a connection between the yellow wire to the JB and the battery positive terminal, the headlight should come on. This means that you can safely test the operation of the headlight relay by connecting the brown wire to the yellow wire while the stator is disconnected.
 
#30 ·
Measured how? The voltage the JB sees in the yellow wire is pulsed DC voltage and never exceeds the charging voltage.
I believe the yellow wire is AC until it goes through the diode in the JB.....then it's PDC. I also believe it is more than the charging voltage under normal conditions. The EMF produced in the stator is based on the number of windings, the RPM of the motor, and the strength of the magnetic field of the permanent magnets, so I don't know how you can say "never exceeds the charging voltage." Maybe I'm missing something here?

When the stator is connected to the R/R, the R/R does not let the voltage on any of the stator legs to rise above the charging voltage.
Since the charging system uses permanent magnets, I don't know how the R/R can affect the voltage produced by the stator.

So, this pulsed DC voltage initially activates the headlight relay in the JB. As soon as the relay makes contact, it self feeds the relay coil, i.e. latches until the ignition is switched off.
Agreed..........


When the stator is disconnected from the R/R, the headlight won't come on because, as I said before, there will be no current in the yellow wire to the JB. On the other hand, while the stator is disconnected, if you make a connection between the yellow wire to the JB and the battery positive terminal, the headlight should come on. This means that you can safely test the operation of the headlight relay by connecting the brown wire to the yellow wire while the stator is disconnected.
Enough with the brown wire already!!!!! :beerchug:
 
#29 ·
Ok, so I wanted to thank everyone as I can see the light at the end of the tunnel now. (no pun intended)

IFixf18s

First off, sorry if I was nasty in my respobnse. I was sitting on my couch soaked to the bone from a 45 min ride in a thunderstorm and was a little annoyed at myslef for taking the bike knowing it was gona rain.

In fact, your information about the relay is kind of what brought the whole picture together for me in my head. And I went back and looked again and found the detailed wiring diagrams you were talking about, and those helped me understand things even better.



Dariv,

Thanks for the great advice, I moved the blue wire today and headlight turned on instantly. I almost moved the wrong blue wire, because there is two of them, then I thought to myself, wait a minute, check the wiring diagram...and I realized the one I was about to move was for the cooling fan. Oops. :smiley_th

Either way, I did this early this morning before I left for work and it was too early to rev the engine up to test voltages, so this afternoon I will go back and test voltages before and after removing the now unecessary yellow wire to the JB.

Furthermore, I am more convinved than ever that my relay is bad, and perhaps this was the cause of all my issues, including why I thought my original R/R was bad. I suspect my charging voltage across the battery will go up once this is removed. I will likely replace the relay in the winter when I perform a full rebuild of the bike (Lofty goals, but I really want to be able to tear it down to every nut & bolt)



pappa,

I am not sure what you mean by pulsing DC voltage to the relay. The wire going to the relay is split directly off the stator wire, and there is nothing on that wire before the relay to change the voltage to DC or to pulse it. As far as checking the voltage, I originally checked my stator at the bullet connectors, which I then removed and soldered the wires together. I have sunsequently tested the stator at the connector to the R/R. Since the splice to the J/B is before this connector, all I had to do was remove the connector from the J/B and test the VAC across that with another one of the stator wires at the R/R connector. Can you explain this pulsing DC voltage to me?

Furthermore, if this is true:

"The voltage the JB sees in the yellow wire is pulsed DC voltage and never exceeds the charging voltage."
.....
"When the stator is connected to the R/R, the R/R does not let the voltage on any of the stator legs to rise above the charging voltage. So, this pulsed DC voltage initially activates the headlight relay in the JB."

Then when I connected the brown wire to the yellow wire in the first place, I would have been connecting DC voltage to DC voltage and should not have had a problem, because the stator was connected to the R/R
 
#31 ·
Kid, first off no biggie. :beerchug: Road home from work today and was a bit wet myself.
Im reading a few things on here and im a bit confused on what your thinking, could be because of some of the advice plus just not knowing a few things.

Im confused about this pulsed DC thing. Never heard of it before in referance to the operation of this bike. We all know that the voltage from the stator is AC (Alternating Current). Everyone refers to the Regulator / Rectifier as the R/R. The Rectifier part of the R/R changes the AC voltage from the stator to DC (Direct Current). This is because the things on the bike needs DC to operate. The lights, charging of the battery, the starter (uses the battery) ETC..... The Regulator part of the R/R regulates how much DC voltage it outputed to the bike. From what ive read the DC has to be below 15V. So the regulator makes this happen. So lets forget about this pulsed DC thing. If you want to learn about AC/DC voltage, operation of diodes or rectifiers just google it.

Ok, Relays. There are several different kinds in relation to how there switched. Ive been used to relays that operate on 28VDC because thats what naval aircraft uses. There are relays that operate on 12VDC and some that will operate using AC voltage. And there are many other kinds depending on the system application. If you look at the schematic and find one of the relays you will notice the coil. One end of this coil has to go to ground, the other end has to go to the source of the operating voltage. You need both the ground and the voltage to make the relay operate. For example if you look at the starter circuit relay in the JB the ground leg of the circuit has to go through the starter lockout switch and the neutral switch. This makes it so the bike will not start unless its in neutral, or if not the clutch has to be pulled in. if this dont happen the starter relay will not operate.

OK the wife is yelling dinner is ready. Hope this helps you understand a bit of how it works.
 
#32 ·
Okay, I will try to explain.

Let's imagine our stator is a single phase device outputting 70V AC when not connected. The situation with a three phase stator is not that much different.



You would imagine that the voltage still is 70V AC when the stator is connected to the R/R? That would mean that the 70V (100V peak) would go directly to the battery through the diode in the R/R. Obviously that is not the case. As soon as the positive going half cycle of the AC voltage reaches the charging voltage, the FET in the circuit starts to conduct, shorting out the stator. The older thyristor type R/R's would keep the stator shorted as long as the rest of the positive AC half cycle lasts. The new FET type R/R's could shunt just enough current to keep the voltage from rising above the charging voltage. However I doubt this because it would generate a lot of heat in the R/R. I believe they still work similar to the thyristor devices and the improvement is just the lower voltage drop across the FET and thus less heat in the R/R.

I don't know how successfully I explained this, but the result is that the (positive) AC voltage never rises above the charging voltage. Well, if you want to split hairs, it does rise one diode drop above.

Dariv is correct in his comment about the pulsed DC only after the diode in the JB. But still, the voltage in the yellow wire is not symmetric AC and never rises above the charging voltage.
 
#36 ·
Weird... I'm not debating; Just trying to understand. 'looking at the manual's elec schematics, I see...what I see, and find it hard to understand how the branched off yellow wire coming from the stator could be anything lower then what the stator puts out (50-70Acv) "before" it hits the JB. Symmetric AC? what is that?

Let's put an extra wire on the diagram written by Pappa (above); branch that wire on one of the stator wires before it connects to anything within the dotted squared off areas of that diagram (for which I'm assuming to be the RR). That (new) wire being the branch going to JB. How will/can that be anything less then 50-70Acv?
The 50-70 VAC output voltage from the stator is measured at "open circuit" (disconnected from the R/R) with zero current. The Shunt Regulator "pulls down" (clamps) the stator voltage by triggering the SCR thyristor as the AC voltage rises causing current to flow. Current flow in the stator windings causes a "back emf" which results in the output voltage being reduced. This is how the regulator can control the stator output voltage "before" the R/R.

Another way to think about is: Since there is only a diode between the input and output voltage of the R/R, how can the input voltage ever exceed the regulated output voltage? (Except by "one diode drop" of 0.5 - 0.7 volt as pappa noted.)
 
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