RGS not charging

M

Magoo

New member
Location
New Mexico
As long as I am pestering you guys I might as well pick your giant brains again.

When I fired it up for the first time a couple of days ago I tested the charging system and found that it was only showing about 12.9 volts. Does that seem right? The only other bike I have that only charges at about that rate is my Genuine Stella 2T scooter. Is that about all I can expect or could it be because I put a nice charge on the new battery before I installed it. It took a bit of cranking to get it started so I was surprised to only get 12.9 even if I gave it some throttle. Do I have a problem? I would have expected at least into the mid 13s.
 
Early bikes came stock with minimum charging systems, they made stronger units in later years. The early bikes didn't have regulators, excess charge went into the standard giant wet-cell battery. Back in the day, you needed to be running pretty hard to keep batteries charged. There are mods you can do to early bikes, the latter bikes were better at this. I love my $20 ebay LED stick to the dash volt meter, to keep the battery charged 14 and a bit is where it should be. An RGS should have 14, it's usually the regulator, or Stator or the dreaded crumbling insulation on the wires, they don't like heat and oil. Get one of those volt meters. More tech people than me will be along soon.
 
Magoo said:
As long as I am pestering you guys I might as well pick your giant brains again.

When I fired it up for the first time a couple of days ago I tested the charging system and found that it was only showing about 12.9 volts. Does that seem right? The only other bike I have that only charges at about that rate is my Genuine Stella 2T scooter. Is that about all I can expect or could it be because I put a nice charge on the new battery before I installed it. It took a bit of cranking to get it started so I was surprised to only get 12.9 even if I gave it some throttle. Do I have a problem? I would have expected at least into the mid 13s.
Click to expand...
One pole of the alternator takes a detour to the headlight switch in an attempt to prevent battery overcharging if running with the headlight off. See if turning the headlight on makes a difference, although the switch can fail also. Most people bypass it. On my bike there was a bullet connection behind the RH sidecover, super easy to unplug the detour and connect directly.
Hopefully it’s this simple, but a good opportunity to check all the 40yo connections between alternator, regulator and battery 😉
 
Subject to no lights on when you measured 12.9v (and your voltmeter being accurate!) then that's low. The RGS Nippon Denso alternator should deliver 14.3-14.5v at 3000rpm. Low volts could mean low battery charge, faulty regulator!/rectifier, or poor connections. I assume you waited a minute or so with the engine running whilst measuring?

As for the throttle, I use a dome headed nut on top of the adjuster. But do take note of Piet's comments on the linkage.
 
The good news is that I’ve got the choke lever mounted. The bad news is that it doesn’t appear to be charging.
I did a search for a regulator rectifier for this bike and it led me to this forum. The info I read was old but gave a reference to a few reg/recs from Kawasaki that could be used.
I also tried to locate the wiring coming from the stator but only found two yellow wires that seemed connected and another yellow that wasn’t connected and I couldn’t find another yellow wire to plug it into. There is also a green wire with a white stripe that is not plugged in.
All of the wiring that I could inspect seemed to be in decent shape and the battery is not being drained.

I’m now begging for any guidance as to how to test the reg/rec and stator on this bike. I’ve obviously got a problem. Is there a common failure that I should look into first? And any more recent tips on what Kawasaki or other parts that would be a good upgrade?
 
Two of the yellow from the alternator are connected directly to the regulator. The third takes a detour through the headlight switch, don't remember the colours, the 3rd charge phase is activated once the headlights are turned on (to decrease strain on the regulator?). You can of course connect the 3rd yellow directly to the regulator as well, no big deal with mandatory daytime lights taking up all the juice that's produced.

If you can find the connectors for those loose wires your charging circuit will most likely be OK and a full 13.8V will show up. The ND alternators are pretty robust and rarely shit themselves. A workshop manual with wiring diagram is quite helpful...

piet
 
You’re giving me hope. I’m glad to hear the stator is a Denso. I was fearing that it might be Bosch or even the Prince of Darkness.
I just came back from the shop. I connected the light and instrument panel.
I checked the battery stagnant and got 12.5. Then I fired it up with the light on and got 12.63 and ran it at 3K rpm for a bit and it never increased. That’s something I guess.
I’ve gotten a few other suggestions since I came in from the shop. I’ll read through them and try again.
I really appreciate the replies! If you ever find yourself in New Mexico I have beer on hand and dogs to pet.
 
I recently had a charging problem. As I understand it you can't test the regulator, but by checking the wiring and measuring the alternator output you can determine if it's the problem. The search function will give you a bunch of info on all of this, especially suitable replacement voltage regulators. The wiring diagram should be on this site as well, or online somewhere.

To test the alternator, unplug the voltage regulator wires...."top right corner under the seat"...along the frame above the negative battery pole.

Unplug the 3 alternator wires. Start the bike...you may need to rev it up to 3000 rpms or so.
With Meter on AC you should get around 75v measuring between each wire of the 3 wires from the alternator and any one of the others....ie you need to measure all 3 phases. Note my bike actually has 5 wires from the alternator but 2 are just duplicates of the other ones. Mine were the same color so it's obvious which they are. Just ignore them.

This is optional, liklely not related to your problem but addessing it keeps things simpler going forward. .....As Piet said you can instead of running the one alyernator phase to the headlight first then back to the regulator, just unplug it and plug it, and unplug the other wire from the regulator that isnt ditectly from the alternator to the regulator, and plug the alternator wire into one of the three going to the regulator. Then ignore the two wires you just unplugged.

As I mentioned lots of info on replacement regulators on this site. I ordered a new Shindegen...note it is physically bigger than the factory one and I have an aftermarket ignition box mounted close to the regulator. So I had to mount the new regulator in a different place. Not sure but if you get an older Shindegen....they are a bit smaller size, and have the stock ignition ...it may fit where the factory one was.

While your at it.....check the fuse box connections. Clean up any corrosion and make sure fuses are seated tightly.
 
After a hiatus from working on this bike I am back at it and have a few questions.

I cleaned the fuse panel and installed fuses I had on hand that were in a lot better shape then the ones that were in it.
As you can see in the pic below I have a yellow wire from the harness and two white with blue stripe. As you can see one of the white with blue stripe is plugged into a white with red stripe. I’m not finding another white with blue stripe to plug into it. I also don’t have any wires to plug into the yellow and green with white stripe as shown in the pic below.
IMG_2882.jpeg

Here’s a pic of the reg/rec that it has. Does anyone know if that is original to the bike?
IMG_2883.jpeg

And just out of curiosity there is a capped off terminal coming out of the CDI. Am I missing something?
IMG_2884.jpeg

And here is the state of the bike. I have have checked the fairing, tank, and instrument cluster for wiring that might give me a clue but nothing comes even close to reaching back towards the battery compartment.
IMG_2885.jpeg
 
Yep rev/Rec looks ridgey didge. Capped off terminal from cdi is a port that with the right lead, plugs into a pc so you can change your ign settings/curves.
 
I figured it was probably original.
Any thoughts on the mismatched wires and the ones that go to nowhere?
I’d also like a recommendation on a new reg/rec that would be more or less plug and play. I’ve still got quite a bit of work to do on this bike but I would sure like to get it charging properly before I go any further.
 
you do not need the cables which go to nowhere,there are 5 cables which come out of the generator but you just need 3, the two others,I do not know, just isolate them.
If the current at the cables by higher revs will not increase the batterie tension to about 14 v the rectifier or the generator may have a problem. Don‘t you have a wiring diagram, isn’t there one in the library?
 
andre g said:
you do not need the cables which go to nowhere,there are 5 cables which come out of the generator but you just need 3, the two others,I do not know, just isolate them.
If the current at the cables by higher revs will not increase the batterie tension to about 14 v the rectifier or the generator may have a problem. Don‘t you have a wiring diagram, isn’t there one in the library?
Click to expand...
I’m newish to the forum. I didn’t know about a library on here. I’ll poke around and see if I can find it. Thanks for the tip!

I’ve been disturbing and cleaning all of the connections just to be sure I gave this scooter a solid chance to make me proud.
Unfortunately I just fired it up again and got the same results.

I’ll be very curious to see if the wiring diagram does in fact verify that the mismatched wires is correct. I’ve never seen that before but maybe it’s an Italian thing.

Given what I know now I’m gonna start the hunt to figure out what rec/reg I need to order.
 
I decided that before I ordered a rec/reg I would look through the boxes of parts I was given and make sure I didn’t have one on hand. No such luck. I did however find a factory shop manual under some shipping materials! lol

So I went to the wiring diagram, realized that I needed my magnifying glass, and then got out my decoder ring and wrote out the color codes big enough that I could see it and translated it to English.

Sure enough, the wiring diagram clearly showed that the green and white wire should have been plugged into the red and white wire instead of the blue and white.

I was giddy! I took a few swigs of beer and made the correction. The bike was started again and in a few seconds smoke appeared from my triumphant new connection. I shut it down post haste.
Defeated, I connected the blue and white back to the red and white wire and was relieved to find that it at least still had a crappy little bit of charging just like before.

There goes my confidence in the wiring diagram. Dare I try the other blue and white wire to nowhere?
Or the other yellow wire to nowhere?

Unfortunately the wiring diagram doesn’t seem to know anymore about this harness than I do. Let’s just say that my frustration level with bike is increasing.
 
That ignition unit is an Ignitech, not the original factory one and a good upgrade.
Have you checked how much AC volts the alternator is actually putting out as suggested by Henry?
Always start there so that you know what you have to work with.
 
Be aware that there are differences in wiring diagrams for different year bikes. I did something similar on my 1975 3c early on in ownership. I had melting insulation on the headlight internal rats nest of wires, so I followed what I thought was correct colours in the repair. It started smoking, and I then noticed that at some time between models, they changed wire colours. The best thing to do is absolutely confirm the year model and make sure you're using the correct wiring diagram, it's all in The Green Book. One of the blokes here made up colored diagrams big enough for blind old buggars to read easily.
 
My factory RGS shop manual shows 3 different wiring diagrams for the RGS....slight variations only.

Your regulator looks very close but a little different than the original one on my RGS. Not sure if it is a different factory one or not.

On my RGS and in the wiring diagrams I have, there are no block connectors near the regulator or fuse box. Wires from alternator to regulator change colors at the bullet connections and are located inboard of the flasher unit near the gas tank strap hook. Other than the larger diameter red one that goes from the regulator to the battery it doesn't matter which 3 from the alternator (as long as they are all different colors) plug into those that go to the regulator.

If the alternator wire that goes to the headlight first before going back to the regulator is still as per factory is causing confusion you can leave it alone...its not your problem...going direct to alternator as I said above is just better and simpler.

I have no idea on the aftermarket Ignition you have. But I don't think the wiring mods for it would change the wiring associated with with the charging system.
 
henrywillms said:
My factory RGS shop manual shows 3 different wiring diagrams for the RGS....slight variations only.

Your regulator looks very close but a little different than the original one on my RGS. Not sure if it is a different factory one or not.

On my RGS and in the wiring diagrams I have, there are no block connectors near the regulator or fuse box. Wires from alternator to regulator change colors at the bullet connections and are located inboard of the flasher unit near the gas tank strap hook. Other than the larger diameter red one that goes from the regulator to the battery it doesn't matter which 3 from the alternator (as long as they are all different colors) plug into those that go to the regulator.

If the alternator wire that goes to the headlight first before going back to the regulator is still as per factory is causing confusion you can leave it alone...its not your problem...going direct to alternator as I said above is just better and simpler.

I have no idea on the aftermarket Ignition you have. But I don't think the wiring mods for it would change the wiring associated with with the charging system.
Click to expand...
Thanks for the replies. I’m gonna head out to my shop in a bit and see if I can apply any of these suggestions to what I am looking at on this bike.
This is a 1983 model and supposedly I am looking at the correct wiring diagram that appears to be incorrect.
I will say that to me the harness doesn’t show any signs of being cut and spliced back together on the rectifier or any other connections.
I have been reading through old posts about this problem and have found several references to this rectifier as a suitable replacement;
www.ebay.com

KAWASAKI 94-09 EX500 EX 500 NINJA VOLTAGE REGULATOR RECTIFIER OEM SH530-12 | eBay

Kawasaki Motorcycle 1990 EX500 - EX500-A4 GENERATOR. Kawasaki Motorcycle 1991 EX500 - EX500-A5 GENERATOR. Kawasaki Motorcycle 1993 EX500 - EX500-A7 GENERATOR. Kawasaki Motorcycle 1989 EX500 - EX500-A3 GENERATOR.
www.ebay.com

If I did purchase this can anyone provide any guidance as to how to wire it correctly?

As for the wire “going to and from” the headlight switch I will attempt to use the diagram to find that wire and see if I can make any sense of that. I am assuming that not having my headlight plugged in is not causing my problem?
I also still can’t get my head around having only one yellow wire coming from the stator to the rectifier and the other yellow wire that goes to nowhere. In my world I’m used to three yellow wires from the stator and accurate wiring diagrams.

Any suggestions are extremely welcomed and I certainly appreciate your input. I really need to get this resolved so I can move forward. I have several of my own projects I would like to get finished and off of my lifts. As of right now I have Laverda parts all over my shop.

Here’s an easy question. I have heard references to an “Executive” model. This bike has the extensions on the fairing, the solo seat cowl, and the hard bags. Does that constitute an Executive? Does that possibly explain the discrepancies in the wiring diagrams?
 
Upon further investigation I have found either another discrepancy in the wiring diagram or vandalism from the previous owner.
The diagram shows that at the fuse box the two connected black wires should be plugged into the 2nd terminal from the left and the orange wire should be connected left of the black wires.
IMG_2886.jpeg

As you can see mine are reversed

IMG_2887.jpeg

Before I create a mushroom cloud can someone verify if the diagram is correct and reversing the wires won’t ruin my day?
 
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