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Discussion Starter · #1 ·
Hello to all.
I have a 03 Yamaha v-star 1100 classic that's been running pretty well, until today. To start with, the battery is about 2 1/2 years old but sitting at rest for 2 days it holds a 12.7 reading according to the voltmeter. I went for a ride, and I happened to notice the meter was reading 12.3 at 60mph.
Has anyone been able to check, with the motor running, what the stator is putting out and go to the rectifier and see what the rectifier is putting out to rest of the system? Sitting on the bike, under the side cover on the left side is the stator wiring harness, on right side under side cover, behind the exhaust is the rectifier. Is there a way to check the rectifier before I start taking things apart?
 

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Between the stator and the R/R there should be 3 wires in one connector.
They often are yellow and come from the stator.

You can measure the AC voltage output across each pair of those wires from the stator with the engine running and the connector unplugged Also check for a ground fault on each wire with the engine OFF.

Each pair should have something like 20 VAC at fast idle and maybe as high as 40 when rev'ed.

If that passes and there is no evidence of corroded or burned connector or wires,
then you are pretty much left with the rectifier/regulator which usually is all one piece and not repairable.

NOTE: Be careful when testing the stator voltage. It can give you a nasty shock.
 

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Discussion Starter · #3 · (Edited by Moderator)
Between the stator and the R/R there should be 3 wires in one connector.
They often are yellow and come from the stator.

You can measure the AC voltage output across each pair of those wires from the stator with the engine running and the connector unplugged Also check for a ground fault on each wire with the engine OFF.

Each pair should have something like 20 VAC at fast idle and maybe as high as 40 when rev'ed.

If that passes and there is no evidence of corroded or burned connector or wires,
then you are pretty much left with the rectifier/regulator which usually is all one piece and not repairable.

NOTE: Be careful when testing the stator voltage. It can give you a nasty shock.
Thanks E.R., I'm not an electrician, can you tell me some more about "checking for ground fault on each wire with the engine OFF" and how would I go about doing that?
 

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Thanks E.R., I'm not an electrician, can you tell me some more about "checking for ground fault on each wire with the engine OFF" and how would I go about doing that?
First you need a multi-meter.
Then you need to find the stator connector.
If you don't have a meter......or don't know how to use it, it would be best if you found someone locally to help.

With the connector unplugged and the engine OFF, you measure the resistance of each stator wire to frame ground.
There should be no current flow; no resistance reading.

Note: I cleaned up your multiple quotes. You can do that yourself too.
 

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Discussion Starter · #5 · (Edited by Moderator)
Thanks again E.R. I have switched from the plastic connector to routing the wires individually using bullet connectors. I'll do what you have suggested and see what readings I get; I'll get back to you, but it may be a while, I'm having problems with the truck too. Merry Christmas, eh?
 

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You are having a REAL problem with the reply quotes on here it seems.
Just leave the automatically quoted part ALONE and add your reply below that.
It really is quite easy.
 

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Just FYI, the Yamaha V-Star 650 is notorious for stator failures. Nothing wrong with going thru all that testing, but if it were mine, just based on the model's history with stator failure, I'd replace the stator and just see. I know, I know. Just Wiily Nilly replacing parts to see if it fixes things is not, generally speaking, the proper way to go about things, but with this model, I'd be tempted to go with the data.
 

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Discussion Starter · #8 ·
@MiseryCity, as stated in the starting post, I have a v-star 1100 classic. You're talking about the v-star 650 being notorious for stator failure. When I get done with my truck, I'll start with the testing E.R. suggested for the bike. As I understand it, he's a pretty solid electrician and been around motorcycles for a long time.
@E.R. yeah, I'm not sure how the "Quote" thing works. In this reply box I see Insert Quotes, Preview and Post Reply. If I click on Insert Quotes, who does Quote from?
 

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@E.R. yeah, I'm not sure how the "Quote" thing works. In this reply box I see Insert Quotes, Preview and Post Reply. If I click on Insert Quotes, who does Quote from?
That quote button will insert text from previous posts that you have already "marked" for inclusion by hitting the "Quote" button while viewing an entirely different post. It is seldom used.......by anybody......and just tends to confuse the issue.

IF, while reading a post, you simple hit the "reply" button at the bottom of that post, it will automatically "quote" that entire post in your reply. After you get comfortable with that, you can edit that quoted text down to just one sentence or so before you actually add your reply at the bottom. Just don't mess with the controls,which are enclosed by brackets [.
 

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Discussion Starter · #10 ·
That quote button will insert text from previous posts that you have already "marked" for inclusion by hitting the "Quote" button while viewing an entirely different post. It is seldom used.......by anybody......and just tends to confuse the issue.

IF, while reading a post, you simple hit the "reply" button at the bottom of that post, it will automatically "quote" that entire post in your reply. After you get comfortable with that, you can edit that quoted text down to just one sentence or so before you actually add your reply at the bottom. Just don't mess with the controls,which are enclosed by brackets [.
Thanks E.R. The truck has a parasitic draw going on. Testing fuses to find out what circuit has the problem. Talk at you later.
 

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Discussion Starter · #11 ·
That quote button will insert text from previous posts that you have already "marked" for inclusion by hitting the "Quote" button while viewing an entirely different post. It is seldom used.......by anybody......and just tends to confuse the issue.

IF, while reading a post, you simple hit the "reply" button at the bottom of that post, it will automatically "quote" that entire post in your reply. After you get comfortable with that, you can edit that quoted text down to just one sentence or so before you actually add your reply at the bottom. Just don't mess with the controls,which are enclosed by brackets [.
Hope you had a good Christmas, I'm still working on the bike, just letting you know I'm still here and I thank you for the info on posting reply's and the problems with the bike.
 

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Discussion Starter · #12 ·
Between the stator and the R/R there should be 3 wires in one connector.
They often are yellow and come from the stator.

You can measure the AC voltage output across each pair of those wires from the stator with the engine running and the connector unplugged Also check for a ground fault on each wire with the engine OFF.

Each pair should have something like 20 VAC at fast idle and maybe as high as 40 when rev'ed.

If that passes and there is no evidence of corroded or burned connector or wires,
then you are pretty much left with the rectifier/regulator which usually is all one piece and not repairable.

NOTE: Be careful when testing the stator voltage. It can give you a nasty shock.
I touched the probe end of a test light to the negative side of the battery (cable off) and the clip end of the test light to a frame ground, and the light came on. I don't think that's supposed to happen, is it? This tells me there is voltage passing through the frame and should see either, melted wires or a fuse that fails repeatedly.
 

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I touched the probe end of a test light to the negative side of the battery (cable off) and the clip end of the test light to a frame ground, and the light came on. I don't think that's supposed to happen, is it? This tells me there is voltage passing through the frame and should see either, melted wires or a fuse that fails repeatedly.
This is NOT meant as an insult but......you don't have a very good understanding of electrical systems.

A test light is mostly useless in doing any serious testing; sometimes worse than useless.

For some of the circuits, the frame IS the negative path back to the battery. For many actually.
If you find the other end of that negative cable, it probably is firmly bolted to the frame fairly near to the battery.

So, with the connection you made, the light lights because of some circuits "charging up" after being disconnected and because of some "computer" circuits booting up before shutting off. Perfectly normal.

If you leave it connected with the light in the circuit, the light should get dimmer and dimmer over a few minutes until it goes out completely. It it stays fairly bright, it might indicate that there is a "phantom current draw" from something that is supposed to OFF but isn't completely. This is with the ignition and any other power switches OFF.
 

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Discussion Starter · #14 ·
Between the stator and the R/R there should be 3 wires in one connector.
They often are yellow and come from the stator.

You can measure the AC voltage output across each pair of those wires from the stator with the engine running and the connector unplugged Also check for a ground fault on each wire with the engine OFF.

Each pair should have something like 20 VAC at fast idle and maybe as high as 40 when rev'ed.

If that passes and there is no evidence of corroded or burned connector or wires,
then you are pretty much left with the rectifier/regulator which usually is all one piece and not repairable.

NOTE: Be careful when testing the stator voltage. It can give you a nasty shock.
No offense taken, 3rd post down from the top I stated I'm not an electrician by trade. Using the method stated above, I got 17-18vac with fast idle and 37vac rev'ed up. I got 0.4ohms for resistance on each of the three stator wires, just touching the meter leads together I got 0.2ohms so the stator looks to be working. Reg/Rec next, this time OEM from Yamaha not a aftermarket POS.
 

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I got 17-18vac with fast idle and 37vac rev'ed up. I got 0.4ohms for resistance on each of the three stator wires, just touching the meter leads together I got 0.2ohms so the stator looks to be working.
I think those voltage readings are WAY too low......assuming that the stator wires were disconnected when the measurements were made.
Then where were the leads connected for your resistance measurements ?
If you had one lead on ground and then the other lead on each stator wire, again disconnected, then your stator is shorted to ground.
 

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Discussion Starter · #16 ·
Between the stator and the R/R there should be 3 wires in one connector.
They often are yellow and come from the stator.

You can measure the AC voltage output across each pair of those wires from the stator with the engine running and the connector unplugged Also check for a ground fault on each wire with the engine OFF.

Each pair should have something like 20 VAC at fast idle and maybe as high as 40 when rev'ed.

If that passes and there is no evidence of corroded or burned connector or wires,
then you are pretty much left with the rectifier/regulator which usually is all one piece and not repairable.

NOTE: Be careful when testing the stator voltage. It can give you a nasty shock.
Testing done on each of the stator wires, unplugged and engine off. "Each pair should have SOMETHING LIKE 20vac at fast idle and MAYBE as high as 40vac when rev'ed" The numbers I got after testing pretty much fit that description.
As to the resistance measurements, according to the voltmeter operating manual a 0.1-0.2 reading is starting point for this meter. all measurements above that would be resistance measured on that test wire or connection at that time. From past experience, I didn't think a 0.2ohms reading meant very much, maybe it does, back to the drawing board.
 

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The numbers I got after testing pretty much fit that description.

I didn't think a 0.2ohms reading meant very much, maybe it does, back to the drawing board.
Your voltage readings are LOW.

And your resistance readings are MEANINGLESS unless you tell us where you were attaching each lead of the meter for the test.

IF.....one meter lead was always connected to ground, then you have a dead short to ground in the stator windings and it is SHOT.
 

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Discussion Starter · #18 ·
I think those voltage readings are WAY too low......assuming that the stator wires were disconnected when the measurements were made.
Then where were the leads connected for your resistance measurements ?
If you had one lead on ground and then the other lead on each stator wire, again disconnected, then your stator is shorted to ground.
I'm going to re-test the stator again. 18vac @fast idle is to low. Another guy with same bike, showed me his bike was getting 28vac. Test done with wires unplugged at connection. Motor running, Meter set for volts AC. Rotating lead clips between the three stator wires.
For resistance measurement, I turned the motor off and pulled key. I set the meter OHMS and touched one lead to ground and rotated the other lead between stator wires.
The other guy measured resistance between the stators only.
 

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OK.....you can STOP testing now.
Your stator is shot. When you take it out, it likely will be burnt to a crisp.
That is the cause of the low voltage AND the short to ground.
 

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Discussion Starter · #20 ·
OK.....you can STOP testing now.
Your stator is shot. When you take it out, it likely will be burnt to a crisp.
That is the cause of the low voltage AND the short to ground.
Yeah... not looking forward to this. Holy Sh... $558+ for an OEM stator from Yamaha! and I'm the guy installing it.
Buddy was getting 28vac at fast idle and high 70'svac at rev. Seems like a lot for the reg/rec to handle. Probably should replace it too.
 
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