Charging system not working

Ok if it’s stock with the black box the two I posted won’t work. They are 1979 to 1974. You need the last picture I posted but that sold today. So make sure you get the right one or you will not have spark. 1980 to 1983 are TCI ignition setups and use a special rotor. If you were running a aftermarket ignition PAMCO/Boyer/Points then you could use the two I still have for sale.
 
Stick with the TCI ignition. You’ll open up a whole new can of worms if you switch over to something else. I switched over to a Pamco camshaft ignition this year after my tcibox failed. It works but It ain’t perfect. Your best bet would be to get the rotor rewound or continue searching for a rotor that has the TCI magnet.
 
Hey everyone,

So I ended up getting the rotor back on it tested perfectly at 4.5 ohm i think. And still i had no charge. I did the slap test again and it feels the exact same, I also have no change in my battery voltage when i rev up the engine, and i tested again from the green wire to ground at the regulator plug. However now i see battery voltage at the brown wire on the brushes attached to the stator. So that is good. At this point however i am completely stumped.

Something else to note is i remember I bypassed the safety relay a while back when i initially purchased the bike. I’m not sure if that affects anything or not but thought it may be worth mentioning. it may also be called the headlight relay or something. I’m not completely sure to be honest.

Any advice would be greatly appreciated.

- Caleb
 
“Well, I don’t think bypassing the safety relay will affect the charging system, but that all depends on what you mean by bypass. Was there an issue with the safety relay? Problems in that area are more likely to affect your ability to start the bike. For simplicity sake and to set your mind at ease, you may want to consider hooking it back up and undoing what ever bypass you did.
I guess this might be a good time to ask if there are any other wiring changes? Were there any changes done to the regulator/rectifier?
In terms of troubleshooting the charging system... I like to start with a good basic diagram. Not the detailed one, but a simplified one such as in the Clymer manual page 179. It shows the basic elements of the system, and will help you focus on what you need to know. The basic elements are: (1) AC generator(rotor, stator, brushes), (2)rectifier/regulator, (3) battery, (4)main switch and fuse, and most important (5) wiring to connect it all together.
I believe you checked the rotor, stator, brushes, and battery. There are procedures for checking the rectifier with a meter. I am not sure about the regulator portion...? The switch and fuse are pretty easy to check. My concern is that something may be wonky with the wiring. Maybe a corroded or broken connection or something bypassed or wired incorrectly? You may have to check all the wiring in the circuit. Pay special attention to the ground connections. They are often assumed to be okay and overlooked.
I helped a neighbour one time who was bobbing his xj650. He disconnected a lot of wiring, literally chopping off things he didn’t think he needed and then couldn’t get it started afterward. Incidentally, he had to reconnect the safety relay. His major problem was that he disconnected the ground connections. But that was different. His bike was basically inert. Yours just has a little charging issue.
You said that you had voltage at the brown wire at the generator. That brown wire goes a few other places. Check that.
 
This makes a lot of sense, the bike has started an run just fine for a while now as long as the battery is charged up so I am with you in thinking it probably isn’t the safety relay. I tested my grounds yesterday and they tested at battery voltage and do not seem to be causing any problems.

However when I got the bike, the wiring around the fuse box was in pieces and i had to stitch it back together. So it’s entirely possible that i disconnected the wire that delivers the charge to the battery. If this was the case, which wire would that be? And where would i look to trace it.

I’m not an electrician but i can handle a wiring diagram.

- Caleb
 
I think it also may be worth saying again that if the battery is low on charge. My electrical will pulse with the stroke of my engine. And when i get it up to speed around 30 mph or so all the electrical works fine. So maybe it is charging everything its just not getting to the battery somehow?
 
image.png Caleb, try this....
 
Sorry. My bad. I kind of pointed you in the wrong direction there. The voltage that charges the battery goes out on the red wire from the reg/rectifier. The brown wire supplies voltage to one side of the rotor and is used by the regulator to control green wire to the rotor. There is a good description of how it works in the tech section. For the battery to not get a charge, there would have to be a break in the red wire where it connects to that main bus. The only other possibilities are the main fuse and main switch being bad. You could check continuity of this connection with your vom. I would do it with the battery disconnected.

I am kind of concerned about your description of the fuse box wiring being redone. As a general rule, most faults are related to previous work done on the bike. You may want to keep this in mind as you are troubleshooting. For now we should assume that the fuse box rewiring was done correctly.

Getting back to basics though. Charge the battery with a charger. Should be at 12.5 volts when done. Start the bike, warm it up. Check the voltage across the battery when you rev the engine up to 2000 rpm. It should be over 14 volts. The manual says to remove headlamp fuse before checking this. Let us know what you find.
 
Hey guys! Thinking about getting back into this project since I’m cooped up in my house for the foreseeable future #corona would love some help in getting my charging system working if anyone would like to help. I never actually finished it because it got cold haha!

I think the biggest lead i have right now is that it does indeed produce power since i can see my lights pulse with my bike while it runs. Does that mean anything or not?
 
Pulsing of the headlight sounds like it is being feed with an ac component. Check your combined rectifier/ regulator for a good ground connection. Check your other grounds.
 
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Hey guys! Thinking about getting back into this project since I’m cooped up in my house for the foreseeable future #corona would love some help in getting my charging system working if anyone would like to help. I never actually finished it because it got cold haha!

I think the biggest lead i have right now is that it does indeed produce power since i can see my lights pulse with my bike while it runs. Does that mean anything or not?
If it's a fast pulse that varies with engine RPM Means your battery is way under voltage or there is a very poor connection between the battery and the rest of the electrical system? A bad ground can be the culprit, or a bad +12 volt wire/connection. For me a methodical R&R of wires, connections, switches etc. is the only way to fly on a 40 year old bike, the odds are good it's several weak areas not just one problem. Worn alternator brushes or a failed diode in the voltage regulator are also possibilities.
 
Okay so my battery rests at 12.5 volts and may go up ever so slightly to 12.7 if i rev the engine up high enough. And i have done the ground checks before but i could be missing something. The troubleshooting guide really makes me scratch my head sometimes. I believe i have checked my reg/rectifier at least 4 times. BUT i could be doing it wrong. Is there possibly any pictures or a video on the site here that may show the step?
 
Hey guys! Thinking about getting back into this project since I’m cooped up in my house for the foreseeable future #corona would love some help in getting my charging system working if anyone would like to help.
OK, I'm gonna offer this piece of advice before I politely bow out of this one... There's 4 pages to this thread. Contained in it is pointers and info from myself, @5twins @XSLeo @gggGary and other extremely knowledgeable people. If you go back and reread these 4 pages, every bit of knowledge you need to fix your problem is contained here.
 
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