Charging issue on a simplified wiring setup

[warrenlevihursh]

I bought a non running project bike that is now running but not charging. The rotor tested bad at 2.3 ohms so I replaced it with a good used one. The bike is a 1978 running points, so I bought a rotor for the early model bikes. I put in on and there was no change. No results on the slap test and no change in voltage when running.

The bike has a brand new regulator/rectifier on it. It may even be a universal type, I'm not sure. My question is what is a solid state RR and should I have bought a rotor for the newer models because I have a all in one RR? Or is the points vs. TCI the only factor in rotor type?

I can post some pictures when I get home from work, I was just thinking about this and wanted to ask. I appreciate the help!

 

[XSLeo]

Ok, The points bikes used a separate regulator and rectifier. The regulator was a mechanical regulator. It used contact points, springs and windings to control the current flow. The rectifier used Selenium plates to convert the alternators AC current to DC. This set up had one brush grounded the regulator supplied battery voltage to the other brush.
The 80 up bikes used the Combo reg/rec. This is a solid state reg/rec. It uses transistors to control the current flow. The rec uses diodes to convert AC to DC.
On this set up none of the brushes had a ground. One brush got battery voltage on the brown wire. The other brush has a green wire that runs to the reg/rec and grounds the brush there.
Basically the early controlled the current before the rotor, the later after the rotor.
The later combo reg/rec is not a straight up swap for the early. You need to rewire the brushes to make it work. Search the three screw mod.
After market reg/recs can be bought for either set up. Early or late, but are not interchangeable, for the same reasons as the stock parts.
Unplug the reg/rec you have, build a set of jumper wires, hook up your meter to read the battery voltage. Start the bike. At the brushes one will have a black wire, this is ground, one will have a green wire, this is battery voltage from the reg. hook up a jumper wire from battery positive to the green wire at the brush.
This bypasses the reg. this will cause the alternator to put out it max output. watch the battery voltage, it should start to climb, maybe rev the engine up to about 2000 rpms. If the voltage rises up then the rotor and stator are working. DON"T let the battery voltage go over 15 volts.
Do you know who made the reg/rec you have and which years it was made for?
Mike's XS sells both an early and a late version.
If it is an early version I have the instructions for it. I'll post them. Follow the wiring exactly.
Leo

 

[warrenlevihursh]

Thanks XSLeo. I can take some picture tonight, but I believe it may have the late RR because I don't remember seeing some of the colors on the instructions you attached. I think the PO might have done the 3 screw mod you mentioned. It does have different nylon screws down at the brushes. I hope to get some time in the next week to use curly's instructions.

Do I unplug the RR at the main connector? I know that main connector from the stator only has a green, black, and 3 white wires. SO... this would be Black (Pos brush, power from battery), green (Power from stator to RR) and the 3 white (just AC-DC wires?).

 

[TwoManyXS1Bs]

Some pics in this post that may help:

http://www.xs650.com/forum/showthread.php?p=437779#post437779

 

[warrenlevihursh]

Thank you guys for the information. I have never heard of this mod but it looks like my bike had it already done by the PO. I was thinking about this at work today, you know trying to be productive, and it suddenly dawned on me what the problem is!

I bought the bike without a battery in it, so when I hooked it up I naturally just wired black to negative and red to pos. There was a small black wire separate from the larger ground wire that I just hooked to neg assuming it was a ground for something. I am not home to look right now, but I am sure this is for the inside brush, which after reading about the mod, should now have 12 volts straight from the battery! Anyway, a dumb mistake, but it should be a simple fix and hopefully the battery will charge now so I can get it rideable. Just in time for winter lol.

Ill post back to confirm, thanks again.

 

[warrenlevihursh]

Bike is still not charging!
I had time to look at the bike wiring again yesterday, and it wasn't an easy fix after all. I was hoping someone here could clear some things up for me. I am using the 3 screw mod and my wiring is new and simplified exactly like the attached wiring diagram shows. (Same colors and all).

Here's what I know:
Rotor is good and in spec (I just replaced it).
Battery is new and good. The bike starts and idles.
Brushes are within spec.
Weak magnetic field, but there is something there.
New solid state R/R, but it could still be the problem.
Stator test to .3, .4 and .4 Ohms when I measure the white wires at plug. I subtracted lead resistance. Is this too low?
I have close to Battery voltage at the black (ungrounded brush) AND the green brush when I switch on the key. Is this correct? Should both have power?
Measured the white to white wires while running using AC on meter. It is basically 0-.1 volts.
I am leaning towards the stator being bad, but wanted some other opinions before I buy a replacement.
Thanks for the help!

 

[XSLeo]

If your reg/rec is set the same as the later model reg/rec's power flows to the brushes, through the rotor and out to the reg/rec where the reg /rec controls the current flow by grounding the brush.
In the stock set up power comes to the brush on a brown wire, A green wire goes to the reg/rec.
With your three nylon screws it appears that it has been modded to work as the later style reg/rec.
Try the slap test, hold a thin feeler gauge close to the nut that holds the rotor on, 1/2 or so, run a jumper from the green brush wire to ground, turn on the key. This should send current through the rotor, creating a magnetic field and the feeler gauge should be pulled against the nut. The stronger the magnetic field the more "slap" you get. This shows your getting enough power to the brushes, the brushes and rotor are working.
Again I suggest a reg bypass test. With the key on you have battery voltage at the black wire brush, the one with the nylon screws, if so use a jumper wire to ground the green wire. Do this with the engine running. With a meter on the battery watch for the voltage to increase, same as I described before.
Can you post pics of your reg/rec? It might help us determine just what your reg/rec is.
The wiring I posted earlier was for the early style reg/rec designed for the earlier separate reg and rec.
I don't have the wiring for the later aftermarket reg/rec.
Leo

 

[XSLeo]

Almost forgot, the .3, .4, .4 on the stator should be ok. The .3 side may be a little weak but ok.
In the diagram you posted it seems to show a stock 80 up reg/rec, the colors match the stock colors. Most aftermarket reg/rec's don't. Some use green as ground. So pics of what you have will help.
Leo

 

[warrenlevihursh]

Ok thank you. Sorry I never posted pictures, I will ASAP. I didn't try the bypass test because I was confused about what to ground due to the mod.

So I will just run a wire from battery negative to the green brush? Do I unhook the green wire at the brush when I do this? Do I keep everything else connected as well?

 

[TwoManyXS1Bs]

Yes, keep everything connected. And do the ground-to-green jumper test exactly the way XSLeo described...

 

[warrenlevihursh]

Ok guys! Jumped to the green wire and have a great slap and the voltage climbed when it was running. So this means the stator, brushes and rotor are good, right? Maybe the RR is bad? Im pretty sure its all wired right. Here is a pic of what i have. Thanks! Hoping to finally figure this out!

 

[warrenlevihursh]

It only lets me post 1 pic at a time. Sorry they are so bad, It was hard to get in there

 

[XSLeo]

From what I can see you have 3 whites, a green, a brown, a red and black.
Those are the same colors as a stock 80 up combo reg/rec.
Are the 3 whites to 3 whites on the stator?
The brown to battery voltage after the key switch?
Is the green to the green on the brushes?
Is the black to ground?
Is red to battery positive?
On the black wire brush is it hooked to battery positive after the switch?
Can you read any brand and numbers on the reg/rec?
Leo

 

[warrenlevihursh]

I found a used stock RR in a box in my garage so I decided I would wire it up and the bike is now charging! I am not sure what was up with the other one but I threw it away. Thank you guys for the tips on bypassing the RR because I never would have suspected that due to it being new. I got to ride the bike around the development a little yesterday for the first time (without it dying). Just have to fine tune ignition timing, carbs and fix some oil leaks and it should be good for spring! Thanks again!