Hey guys, I have a strange electrical problem that I hope some people can help shed light on.

Two weeks ago, I was in the middle of a ride when my bike started sputtering and was hardly staying above idle. The moment I gave it some gas to bring the revs back up, it died. I turned the bike off and on again to try to start it but my bike wasn't getting any power. The oil and neutral light comes on but no headlight, signals, horn, etc. Dead battery? How? I take the battery out, leave the bike, and head home to charge it for a few hours to see if it does anything. A few hours later, I come back to see if there was enough juice to start the bike but again, there was no headlight or any other response. I was prepared to jump it anyways, so I hook the bike up to a car (car is off) and there was still no response. However, I connected the cables from the car terminals to the bike terminals and I recently read that you should connect the negative cable to an unpainted metal point on the bike as ground. I'm not sure skipping that caused my jump to fail. I wasn't confident enough to bump start the bike and ended up having to push it home about a mile.

Fast forward a week and I'm home again to take a look at my bike for a second. After the push home last time, I just left it in a garage without putting the tender on. I stick the key in for the heck of it and see that the lights turn on. Horn and signals work. I pull the clutch and hit the starter and the bike starts.

I'll mention that this is not the first time that this has happened before. There has been 2 or 3 times where I've come out for a ride, stick the key in, and have no response. I end up going back inside and researching on the boards for a while. Then, after a few days, I try the bike again. Key in, lights on, signals work, and engine starts. I've ignored the problem since until last week, all it's cost me was a day's ride. But the most recent incident happened on a ride, in the middle of the night on a Sunday where my options were to call for an expensive emergency tow or push it home.

I have a multimeter and plan to test the battery when I'm home this weekend. It's a 2 year old, cheap, autozone battery so I guess I shouldn't be surprised if it's hardly holding a charge. However, the first incident happened sometime last riding season when the battery was only a year old. I've always brought the batter inside and left it on a tender in the winters.

Can a crapped out battery be the cause of these problems? Does anyone else have any suggestions?

(I've attached a photo of my bike in the parking lot where I left it while I took the battery home to charge)

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Sounds like an electrical problem somewhere.  Weird that the headlight doesn't turn on when it doesn't work.  Isn't the headlight cutoff part of the starter switch in the later models?  Someone with more electrical knowledge should be able to help here. 

I ride a 2006 model and it doesn't cut off the lights when I start it.

However, I don't think it's a problem with the battery. You see, when you start the bike, you can disconnect the battery and it should keep running just fine, all the lights should remain on etc...
Must be something else, not sure what though.

The only heat related electrical issue I ever faced was with a faulty pickup or pickup wire. Bike would run fine for about 10 minutes until it got warm and then would die instantly and couldn't be started for several hours. I replaced the cable to the pickup  and it was fine. Not sure if this is your problem, but it sounds similar. There is no way to test because the electricals will show the correct values on a multimeter when its working, and when it stops working there is no signal coming from the pickup so there is nothing to test. All you can do is replace and see what happens.

That is an odd one.....I'm guessing the headlight is normal (not HID, or a high power H4)?

The only heat related problem I've had that is similar are the ignition coils overheating. But that bike was over 40 years old. For the headlight to be off though? I dunno......maybe there is a short around your starter button, shutting the light off and draining the battery? Just stabbing in the dark I guess.

Check the charging system (stator, R/R, battery voltage, clean grounds, starter circuit, etc) and post back here.

Quote
I ride a 2006 model and it doesn't cut off the lights when I start it.

However, I don't think it's a problem with the battery. You see, when you start the bike, you can disconnect the battery and it should keep running just fine, all the lights should remain on etc...
Must be something else, not sure what though.

False, the GS needs a battery to run and stay running.

Quote from: robfriedenberger on June 06, 2014, 12:51:12 AM
False, the GS needs a battery to run and stay running.

You really want me to make a video about it?

Quote from: jsyzdek on June 06, 2014, 11:58:02 AM

Quote from: robfriedenberger on June 06, 2014, 12:51:12 AM
False, the GS needs a battery to run and stay running.

You really want me to make a video about it?

yes please 

Quote from: jsyzdek on June 05, 2014, 09:58:05 PM
you can disconnect the battery and it should keep running just fine,

Clarity for any future newbs:

You can disconnect the POSITIVE side and it should remain running with all lights. 

Do NOT disconnect the NEGATIVE while the bike is running. 

Quote from: cWj on June 06, 2014, 08:08:37 PM

Quote from: jsyzdek on June 05, 2014, 09:58:05 PM
you can disconnect the battery and it should keep running just fine,

Clarity for any future newbs:

You can disconnect the POSITIVE side and it should remain running with all lights. 

Do NOT disconnect the NEGATIVE while the bike is running. 

I happened to have disconnected both last fall and it just kept running...

Thanks for the suggestions and sorry for the late response everyone.

I busted out the trusty multimeter today and started testing the battery and going through Kerry's guide on the FAQ (http://gstwins.com/gsboard/index.php?topic=38480.0) for testing the charging system. Both his guide and my Hayne's manual were super helpful. I felt that I learned a lot about the wiring and charging system on my bike today.

The bike has sat with a tender since last time so the battery should be good. It reads a healthy 12.77v when I put the prongs on the battery screws but when I put the prongs on the metal plates that go on the terminals, the number constantly varies greatly between 3v and 12v. Is that normal? I would think that it should read 12.77v since the metal is touching the terminals. The undersides don't look too rusty or corroded.

I turn the key to on (all lights/horn works), voltage drops and holds at 11.68v. Not great.

Start the bike and the voltage hovers around 12.5v but also fluctuates from 9v to 13v. From my research, it should be bouncing mostly around 12-13v, not 9v.

The bike is having trouble idling (my fault, didn't really warm up with the choke) and the engine cuts out. I reset and try to start her a couple times with no response (no lights/horn). After 2-3 mins of waiting and trying, I catch the headlight turning on, press the starter, and she roars back to life. The tachometer doesn't work until a few moments later however. Since it's an electrical tach, I'm guessing it's affected by whatever problem I'm having. Revving the engine doesn't increase the battery voltage above 12.5v. This is bad 


Here I start testing the alternator prongs to the negative terminal with my multimeter set to ohms. Each of the three prongs to the negative terminal read "infinite" which should be the norm.

Next, I test each of the three alternator prongs to each other. They all read around 1.9-2 ohms. Kerry says they should be fairly close to zero so I think I'm alright here. However, when I tested, the values would jump right to 1.9-2 ohms or fluctuate greatly between 50 or -1. I tried to replicate where that happens but it seemed to occur sporadically. This occasionally errant behavior worries me...

I then switch on the bike and have someone help me twist the throttle while I test the alternator prongs to one another. Kerry says the readings should all be equal to or greater than 75 ohms but my multimeter shows no response at all  I tested multiple times but I couldn't even get a blip to show on the multimeter. Turned the bike off.


Next, I tested these two plugs coming from the regulator. I follow the instructions in my Haynes manual and test all the prongs and sockets against each other. Most tests are supposed to show a reading of "infinite" which I do get. However, some combinations are supposed to read 6 ohms or 40 ohms and when I go to test those, the multimeter would jump to ~150ohms and then to "infinite".

What do you guys think is going on? Both my alternator and regulator are shot? My battery doesn't get charged at all as I ride? That would explain it getting cut off right in the middle of a ride... I rode on battery power until it couldn't handle it anymore. But how come leaving my bike alone for a bit will eventually allow it to start? Why didn't my jump from a car work? Are there more tests I should perform? What needs fixing/what parts need replacing? Thanks in advance.

Sorry Alex, I'm not much of an electrical guy. I want to say your battery is bad from the get go (should be higher than 12.CC volts from sitting on a charger).  But if you have some time and want to look into some more tests, here are some for the older GS bikes (70's and 80's, but similar to the 500):

http://www.thegsresources.com/_forum/showthread.php?t=152769

Whatever the problem may be, don't try to skimp on one part or another. I mean, I've seen a R/R go bad which burns up a stator......which kills a battery. So if your stator gets replaced and you hook it up to a bad R/R, it can put you back at square one.

I found this helpful for testing the stator:



And this for the R/R:



The impedance test to the negative post seemed to indicate a bad stator. I decided to go ahead and take a look inside the cover. This is what I found:



I changed the left cover gasket this past October and those coils were a lovely copper hue. I believe I murdered it with the conventional battery that likely sat too long without being charged this past winter. FtR, the stator seemed to be putting out only about 10v at idle with a brand new battery charged to 13v would fall to 12v after riding. In fact the voltage at the batt has gone back up to 12.6/7v after the bike has sat for a few days. It's higher while SITTING than with the bike running at 6K RPM.

cWJ, it sounds like you had exactly the same problem that I'm having now. From the looks of it, I need to get a new stator and R/R and while I do that, I'll also pull out the original stator to see if anything physically looks wrong. Also have to check the rest of the electrical system to see if anything caused this... maybe a short somewhere.

Just found out some great news this weekend. I was reading up threads on bad stators and came across a comment left by adidasguy politely reminding the OP that the multimeter must be set to AC when testing the stator, not DC. That made me think... did I do that? Reread Kerry's instructions and sure enough, it said to set it for AC voltage when testing. I must have skipped over that line when reading. Adidas still helping us each and every day.

I went back today and tested the alternator connectors to ground and they all show a reading of 70v. Not as high as the recommended 75v but I would say it's close enough. I reread the instructions and tested my R/R again. Same result as last time, dead. Now I've narrowed it down to only one thing needing replacing instead of two, which is a win in my book. The Caltric R/R seems to be well liked around here so I'll put in an order and hopefully get it by next weekend. I'll still look around for shady wiring and shorts just in case but hopefully it's only a bad R/R that's been causing all my problems.

Good diagnostic work here; hope this problem is solved now. Please let us know how this turns out...

I was able to get my charging situation back in order. I replaced my toasted stator with a low mileage example from an '04 and a R/R from an '06. All is now well. For those dealing with this in the future:

- As AdiidasGuy said in another post, a newer (01+?) stator plugs straight into the R/R. You don't need to splice anything on older bikes with the 3 wires going to the plugs in the harness on the left side of the bike. Just route the connector from the stator up to the R/R and plug straight in. The persnickety should feel free to then remove the excess wires and connector.

(Yours truly is currently not so bothered)

- When I first plugged everything in and connected the mulitmeter, I was getting my proper AC voltage from the stator, but was worried when the voltage kept going down when revved to 5K compared to idle. Then it occurred to me that this was due to the regulator half of the R/R doing its job - lowering voltage at higher RPM to keep from overcharging the battery. During this discovery process I tested the old R/R with the battery lead disconnected and it was sending about .2-.4 fewer volts to the battery. The decision to change it proved prudent.

- It became apparent how much a properly working charging system effects the performance of the bike. While it was running, I unplugged the stator to meter it and the bike's RPM instantly picked up with the reduced load.

- During this month of investigation and bartering over prices and waiting for parts, I bought some NGK Iridium plugs. They do seem to help a bit with the cold starts. We'll see whether that still seems to be the case when the temps go back down.

For now a ride is in very much overdue order.

Can someone help confirm what setting I need to have the multimeter in order to test the R/R? I received my new one in the mail and decided to test it against the ohm values stated in the manual. I turned the dial to 200 ohms and to my surprise, got the same results as my old one, nada. Some wire combinations should be reading 6 ohms or 40 ohms but I get nothing from both R/Rs that I have. I test both using the diode setting instead and get readings where I'm supposed to. Now I'm stumped again as it seems that my old R/R could have been working fine.

If you're looking at a Suzuki service manual, you won't get the same numbers unless you're using the Suzuki tool. As I read it, the more difference between the numbers from each wire during the diode test (aka: "inconsistent"), the dodgier the r/r.

When you test in diode mode, also be sure to switch bias (see Rick's video I posted above).

You might also check to see the DC voltage it is putting out by starting the bike and disconnecting the plug going to the battery (two-wire connector). With the meter set to the 20v range, my old r/r put out .6-.8. The newer one put .8-1.

I'm not sure what number is considered to be "in spec", but the diode test did show the old r/r to be less consistent.

Is there are battery dealer near you that can load test your battery?

That's true, there was a note in the Haynes manual stating that if you don't get the ohm values posted then go to a Suzuki dealer. I suppose they meant that a Suzuki tool might be needed for testing.

I followed the link above when testing in diode mode and the new RR does seem to be more consistent. Less than 10 values in difference. The old RR was about 25. However when I tested it while the bike was at idle, the old RR put out ~1.5v and the new one put out ~6.2v. That seems way high... I put the 2-wire connector back together and checked the battery. It now can get to about 13.5v when I rev it but still seems a bit far from the recommended 14-15v that I see on youtube.

Would the battery test done by autozone be sufficient? I'm going to get a Motobatt MB10U anyways so that I can eliminate a shoddy battery from the potential list of causes. Just trying to get back to riding