Okay, my GS500E won't charge the battery. Output from alternator checks out good, -reads 75 VAC across the 3 wire pairs. Reg/Rec (known good replacement) fitted. Charging curcuit connectors and wiring checked for continuity.
Still nutt'n. The bike starts on the button and runs nicely but no charge to the battery. Is there anything else in the electrical system I should check? Any other components that could influence the charging system, eg sidestand switch and relay?.. the little 3 pronged diode? Ignition switch?
Any ideas? -I'm starting to get a bit pee'd off with this!!!
-Jools

Is your battery good? Could be old and not able to hold a charge anymore, possibly some dead cells.?

By the way, you can get tor battery checked at pretty much any auto shop.

Got a brand new quality battery fitted. Not an issue anyway, as I'm not getting the right output from the rec/reg output terminals (before the battery).

The output of the regulator needs to be connected to the battery and read the voltage at the battery. If low, then your regulator needs replacing. We've had to replace a few here.

Reg same for all models of GS500 so if you buy a new one, or a used one, get the newest you can get.

I've tried 3 regulators, the original one, a 'guaranteed tested ok' used replacement one, and a new one. No joy, they all give about 12v-12.3v at the battery terminals regardless of revs.
That's why I'm wondering if there's anything else in the circuit that could affect charging.

What might be on the bike that is loading it down?
What if you unplug your headlight (just as a test)
Your meter? What type? Digital or analog? If digital, is the battery good?
What does it measure on a good, new AA battery? A 9v battery? That can help determine if your meter is bad.

Hmmm, the crappy thing about charging systems is if you are trying to trouble shoot to find out which part of the system is actually faulty, you can ruin the good parts while operating the system too much with the faulty component, whether it be the battery, stator, or RR.

I know it sounds trivial but I would take the battery to a shop and have them check it for free, and possibly a new RR. I bought my cheapo one from Caltric (~40) on ebay and it worked great. Usually those components are the problems, not the stator.

As I said, tested with x 3 RR's (one is new), 2 batteries (one brand new).
I have one digital meter and one analogue type, they check out ok. The charging circuit looks simple enough, but maybe some other component is influencing it? What about that sidestand relay... I would have thought it's only for the starting system but maybe not? Ignition switch? bear in mind that the bike is starting and running well, just not charging.

Waay year of bike?
Does your stator have 3 barrel connectors or a 3 pin molex type connector?

Quote from: Joolstacho on January 11, 2014, 05:06:35 PM
The charging circuit looks simple enough, but maybe some other component is influencing it? What about that sidestand relay... I would have thought it's only for the starting system but maybe not? Ignition switch? bear in mind that the bike is starting and running well, just not charging.

The only component between the reg/rec and the battery is the fuse.  The sidestand relay, ignition switch, etc affect weather or not the bike will run.

Charging issues can typically (especially when the bike runs) be narrowed down to the battery, stator, reg/rec, wiring (short or disconnect), or excessive load on the battery (i.e. powered accessories such as lights, hand warmers, etc).

To rule out load issues, adidasguy suggested disconnecting the headlight and other accessories.

Since you have a new battery and new reg/rec, I'd guess that the stator may be causing an issue.
To test the stator, disconnect the stator and check for the following:
a) engine running 4000 RPM, should read 75 VAC across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
b) engine off, make sure you have continuity across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
c) engine off, verify there is no continuity to ground from Y1, Y2, and Y3 of the stator.
If all of those tests check out, then the stator should be fine and you may have a wiring issue.

'89 Bike, 3 barrel connectors from Alternator.

"a) engine running 4000 RPM, should read 75 VAC across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
b) engine off, make sure you have continuity across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
c) engine off, verify there is no continuity to ground from Y1, Y2, and Y3 of the stator".

Done these checks (above) and checked the fuse, I'll double check continuity from fuse to battery.
I'll try disconnecting headlight, (but I would have thought it should charge in spite of anything like that, so maybe in the circuit something mysterious happens 

Cheers boys, appreciate your help.

Next check would be to look around for shorts. Most likely where the wires go into the headlight bucket, lots of times the protective coating gets ripped and exposes wires that short out there. That happened to me.

Quote from: Joolstacho on January 11, 2014, 09:28:36 PM
'89 Bike, 3 barrel connectors from Alternator.

"a) engine running 4000 RPM, should read 75 VAC across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
b) engine off, make sure you have continuity across Y1-Y2, Y2-Y3, and Y3-Y1 of the stator
c) engine off, verify there is no continuity to ground from Y1, Y2, and Y3 of the stator".

Done these checks (above) and checked the fuse, I'll double check continuity from fuse to battery.
I'll try disconnecting headlight, (but I would have thought it should charge in spite of anything like that, so maybe in the circuit something mysterious happens 

Cheers boys, appreciate your help.

Then it looks like your stator is fine.

With everything working correctly you and the bike running at 4000 RPM you should have 13.5-14.5 V at the battery (charging); with 12-12.3 V (that you stated) it's possible that the reg/rec is faulty, though this doesn't seem likely since the same issue is present with 3 different reg/recs.  Just to be sure, here's how to test it.

Disconnect both of the plugs to the reg/rec and check for continuity as follows.
a) negative probe on B/W wire; should have continuity to Y1, Y2, Y3, and R
b) positive probe on B/W wire; no continuity to any other wire
c) positive probe on R wire; should have continuity to Y1, Y2, Y3, and B/W
d) negative probe on R wire; no continuity to any other wire
e) should not have continuity between any of the Y wires in either direction (e.g. check + to Y1 and - to Y2 as well as - to Y1 and + to Y2)

If any of the above fails, the rec/rec is faulty.

If the reg/rec checks good, then the next thing I'd check is for damage in the wiring between the reg/rec and the battery.

Your bike has an intermediate run of wire from 3 barrel connectors to the 3 pin connector for the stator.
Check the continuity of those 3 wires.
Newer bikes had a 3 pin connector on the stator that went directly to the regulator.,

In this photo, you will see 2 of the 3 barrel connectors at the top center (yellow and white). Outside the frame in the middle below the brake reservoir is the other end of it, pointing up and not connected to anything in this photo.
One wire from one end to the other might be broken.



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Adidasguy... Yup, done all that...  checked a dozen times! Also checked the red to the ignition switch, connectors and H/L etc.
(Thanks for going to the trouble of taking the pic mate).
Still nutt'n!

Rado, I've done the tests you suggest. But I need to clarify... my meter only goes down to 200ohms, I can't get any readings on the ohms scale, but if I switch to the Diode position I get readings as follows: POS(lead) to Green, reading approx 500 to all others
NEG to green, No reading to others.
NEG to red, reading approx 500 to all others.
POS to red, No reading.
No reading between the yellows in either direction.

Quote of my day...
"Just because I'm paranoid, doesn't mean they're not out to get me!"
 

Quote from: Joolstacho on January 12, 2014, 02:39:33 AMRado, I've done the tests you suggest. But I need to clarify... my meter only goes down to 200ohms, I can't get any readings on the ohms scale, but if I switch to the Diode position I get readings as follows: POS(lead) to Green, reading approx 500 to all others
NEG to green, No reading to others.
NEG to red, reading approx 500 to all others.
POS to red, No reading.
No reading between the yellows in either direction.

Never heard of a multimeter that didn't go down to 0 Ohm (i.e. short circuit or continuity).  But the diode mode works as well since you're essentially testing the diodes in the bridge rectifier.

The reg/rec should have a red wire (R) and black wire with white stripe (B/W) going to the battery and 3 yellow (or black as in adidasguy's pic) wires (Y1, Y2, and Y3) going to the stator.  Could you post a pic of your actual reg/rec to verify wire colors and plug configuration.

Assuming that the green wire is connecting to the bike's neutral (B/W), then your measurements on the red and green wires are exactly opposite of what you should be getting meaning that those 2 wires are reversed.

Rado, to clarify.
The 'new' RR has 3 yellows, red, green. It's off a different Suzuki model that my mate, a M/C mechanic uses as a tester (I'm connecting green to black and white in this case cos it's the earth side).
The original RR off my E model has 3 yellows, red, black and white.
The 'replacement' RR off an '07 model has 3 yellows, red, black and white.
each one tests similar figures in the diode position.
Is it possible that something could have reversed the polarity of all 3 RR's? Wierd !!!

Quote from: Joolstacho on January 12, 2014, 04:49:53 PM
Rado, to clarify.
The 'new' RR has 3 yellows, red, green. It's off a different Suzuki model that my mate, a M/C mechanic uses as a tester (I'm connecting green to black and white in this case cos it's the earth side).
The original RR off my E model has 3 yellows, red, black and white.
The 'replacement' RR off an '07 model has 3 yellows, red, black and white.
each one tests similar figures in the diode position.
Is it possible that something could have reversed the polarity of all 3 RR's? Wierd !!!

Just out of curiosity, what type of multimeter do you have? Pic?
You keep saying that it only goes down to 200 Ohm.  Are you talking about what it says on the dial for the mode selector?  If so, then the 200 Ohm setting is high precision 0-200 Ohm and anything over 200 Ohm shows as O/L (over level) or no reading.

Out of curiosity, I pulled out my DMM and tested the reg/rec in my bike (no charging issues) and there it was also reversed (opposite of what the table in the service manual says) so I get continuity with the + probe on B/W as you do.
Next I went back and looked at the schematic diagram for the charging circuit; based on the schematic (diode arrangement), it makes sense that with the + lead to B/W you get continuity to R and the Ys and you don't get continuity with the - lead to B/W.

Conclusion is that the Suzuki pocket meter has the leads for their Ohm-meter wired bass-ackwards; probably so the mechanics can simply go red probe to red wire without having to understand how the reg/rec actually works.

So if all 3 of your reg/recs test the same, then they should all be good.

Sorry mate, what I mean is that the lowest RANGE is 200ohms.
My meter is just a standard cheapo digital meter, (it's yellow)  - looks the same as Radio Shack ones that I've seen, but it's been good enough and reliable for years. Good that you clarified the RR polarity thing, ta.
My sidestand switch doesn't seem to work (no continuity in up or down position) it looks solid state... is it a simple switch or what? Then there's the sidestand relay, I can't see how it could affect the charging circuit but maybe it could? (I have a spare relay I could substitute). The other thing in the charging circuit is the ignition switch, I've checked continuity in the loom ok, plugs okay, I wonder if it's possible that there's an internal fault in the ign switch contacts, but remember that the bike starts and runs well. (clutching at straws now I am!)
I should clarify: I'm working from wiring diagram P420 & 421 of Clymer manual titled "'89 GS500EXCEPT UC and Canada models" I have now got off ebay: a rotor & starter clutch assy, stator and cover assy, a wiring loom (which is different I know) -all off an '07 model. I have these as 'backup'.

Quote from: Joolstacho on January 15, 2014, 06:52:39 PMThe other thing in the charging circuit is the ignition switch, I've checked continuity in the loom ok, plugs okay, I wonder if it's possible that there's an internal fault in the ign switch contacts, but remember that the bike starts and runs well. (clutching at straws now I am!)
I should clarify: I'm working from wiring diagram P420 & 421 of Clymer manual titled "'89 GS500EXCEPT UC and Canada models" I have now got off ebay: a rotor & starter clutch assy, stator and cover assy, a wiring loom (which is different I know) -all off an '07 model. I have these as 'backup'.

Going from the wiring diagram from the Suzuki manual (and on the GStwins wiki) the output of the stator does not even feed through the ignition switch.  i.e. if you were rolling down a hill with the bike in gear and the ignition off you would still be charging the battery.