Alternator, Stator and Regulator

I'm following this thread and didn't want to hijack...
http://www.xjbikes.com/forums/threads/electrical-meltdown-dont-even-know-where-to-start.68806/

Went for a 1400 km solo tour last month. Made it about 1200 km!

On the last day the charging system stopped, and I ended up with a dead battery and no go.
... The story goes on...
Now I have an intermittent charging issue!

Charged up the battery and the bike started right up . charging @ 14.5 @ 4000 RPM. Right in spec.
I have been checking everyday after my ride home from work. (Always late in the AM)
And the charge @ 12 ish.

When at idle it was initially @ ~12.5 and when revved to 4000 would jump right up to 14.5v.
The numbers have been slowly getting smaller.

Yesterday I noticed that it climbed slowly from 12.5 to about 14.2 and then stopped.
Today it was @ 11.7 and barely 13v @ 4000 rpm.

I know where the alternator/charger is, and have removed the cover to inspect.
- The brushes are still about 1/2 " and the brass plate is shiny where the brushes make contact.
- I have disconnected the tail lights, tank low fuel light and removed all fuses except the ignition.
Same condition.
I'll bet you if I take everything apart again (3rd time),and plug it all back in I have full charge!

Is the regulator the aluminum square with fins? (Pic attached)
Should it be too hot to leave my hand?
Is the stator the other box on that side panel? ... What does it do?

I am going to check and clean all the connections, but they are pretty good already I think.
Does this sound like a faulty regulator?

 

yes thats the regulator and there is heat involved
what bike do you have?
How old is the battery?
do a voltage check when you start bike you wat to record volts pre start then voltage when you press start but before it actualy starts
the stator is the coil around the alternator slip ring
this thread has some info for you
http://www.xjbikes.com/forums/threads/1981-xj-550-rectifier-stator-questions.63406/

 

Regulator is the finned square as you mention. The stator is in the alternator housing. It's the round bunch of wound wires that sits around the rotor which has the brass rings for the brushes (as you indicated above). Stator should be OK.
I hate intermittent electrical issues! My guess is that it's the regulator/rectifier. If it's an original one they weren't all that great to start with. The fact they lasted so many years is a miracle in itself. Perhaps some other here can assist in how to test the reg/rect.

 

check your battery connections make sure they are clean and tight. clean the negative battery wire connection where it connects to the frame.
acid battery check the acid level make sure all cells are between the lines if fluid is needed add distilled water ONLY. it is available at most supermarkets.
thread link has all the testing info for regulator clean the regulator connections

 

That has not been the experience of anyone that I know, including a few former Yamaha techs. It is possible that the Austrailian market bikes got a different regulator than the NA bikes did though.

Regardless. OP should go through the checks that XJ500H recommended. Voltage regulators don't last forever. Heat kills components, and regulators get hot.

 

around the solenoid area there should be a 3 conductor white plug with 3 wires that have white cloth insulation, they go from the alternator to the rectifier.
that plug could be the problem

 

from XJ4ever catalog
NOTE: Alternator brushes should be replaced whenever they are less than 11mm in overall length......the factory maintenance interval indicates that you should expect to replace these brushes every 8-10,000 miles. Factory brushes have "wear marks" (scribed lines) on the brush to indicate their wear limit; these aftermarket brushes also have the scribed wear line. Overall length of these brushes are 17.10mm, with 9mm of length from the wear bars to the contact end of the brushes:

you said "- The brushes are still about 1/2 " and ...." is that overall or wear line to working end
11mm is .433 of an inch
you may just need new brushes

 

Thanks folks,
Some responses:

1) Intermittent electrical issues are hateful indeed. I have 2 XJ's like that right now!
- Better than not having any XJ's though.

2) This bike is a Maxim-X 750 - battery late last year - levels are OK (1 cell needs a touchup).

3) I got rid of most of the plugs, and hard wired many of the connections.
I know... I know... I'll put 'em back.
Checking the connections again along the way. Whats the Solenoid.

4) Brushes too low... I like that! ... 1/2" overall.... I'll check for wear lines.

 

the solenoid is what sends power to your starter when you push the start button, its a large relay.
still best to do a full check on your charging system and connections before you start spending cash, at 1/2 inch overall if is not your problem now it will be soon.
good luck

 

Check all wiring connections downstream of regulator. As in pull apart and check for corrosion. Bad connection will give the symptoms you describe. See also: https://www.electrosport.com/media/pdf/fault-finding-diagram.pdf

 

Brushes are fine I think..
- I added a pic of the brushes and the plate.
- The wear line is clearly visible.

Starting the connection checks now...
How about corroding wires.... ?

The 2 wire shots are the positive battery pole.
The red wire is rust brown, and has white corrosion dust when fiddled with.
Stripping it closer to the pole... it's pretty much the same all the way.

I assume rusty, brittle wire doesn't maintain it's properties and should be replaced.

(The white wire is just a piece of new, clean, similar gauge wire... and it's nice and shiny.)

 

I replaced the "rusty" red wire... No issues since.

 

Strong work!

 

so did you replace the red wire with "a red wire" of similiar gauge or with that "white wire" ??

...it is always best to replace with like kind for traceability down the road.......

Just my thoughts....

 

Yeah - That was a tough fix. lol...

I used the white wire, but I agree and WILL source the original gauge and colour for traceability in future.

 

Or wrap it in red electrical tape every few inches.

 

if it goes where it should, doesn't matter what color it is. whole sub-stations are wired with gray wire

 

But sub-stations have easy-to-read, full-scale, 3-dimentional wiring diagrams.

 

Back in the day when I was trying (and failing) to become a radio repair tech for the Marines, there was one particular radio whose components were contained in a large number of self-contained modules. Each module had a number of leads sticking out the bottom where wires were soldered onto. It was, therefore, rather important that the correct color wire go to the correct lead on a given module, even with the schematic handy - for troubleshooting purposes, as there was a spaghetti maze of wiring visible when one opened the bottom cover.

The instructor guiding us through this particular radio related a tale about how one had come back for repair. When the bottom cover was opened, they were greeted with a rather dismal sight. All the wiring had been replaced. Every. Single. Wire. Was PURPLE.

Their solution: Tag it and send it to the regional repair depot.

 

I've got some purple wire if you need some. Hehehe