Charging system question/issue

[Anonymous]

Hi All,

I have a 1980 GS550L. I am having a problem with the charging system. What happened is I was riding the bike, I came to a red light, a long one. I am sitting there, in first gear, clutch in, at idle. The buck starts to idle roughly, I give it a little gas and it seems to respond back to normal, for about 20 - 30 seconds. I give it a little gas again, at this point I am trying to keep it from stalling out. I notice that my blinker is not blinking, the indicater light is on solid. I give it some more gas and the blinker starts to blink, but not very fast. The more I rev it the the faster it blinks.

I make it through that light and I come to another one. The same thing starts to happen again, but this time it stalls. I hit the button to restart it and, nothing. No click, no nothing. I eventually have to push start it. I was on lunch, I make it back to work, shut it off, and it starts up. About five hours later I get out of work, I go to start it and again, nothing, I have to push start it again. At this point I am just hoping to make it home. I struggle with it the whole way home, but manage to keep it running by keeping on the throttle to keep up the RPMs even at stop lights. I the try to restart it once at home and the battery has enough power to just barely make the starter moan over a couple of times, then again, nothing.

I go out this morning to try to see if it will start and, you guessed it, nothing. I hook it to a charger and I get it to start. It seems to be idling ok. I put on one of the binkers and it doesn't blink. I rev the bike a bit and it blinks, just as above. I let it idle and it eventually just stalls. I have to boost it again to start it. I turn on one of the blinkers and the thing starts to idle rough like it is going to stall, I rev it , then again it is rough, I leave it alone and it stalls.

I have an issue at times when I start it to begin with. Sometimes the relay just clicks, I have tracked that problem down and it is the heavy blach wire that comes of at the relay and then attatches to the start is loose at the connection to the starter. If I wiggle it it has always started right up.

I don't think these two issues are related because I can't figure out what a loose wire at the starter would have to do with something not letting the system charge, but I may be totally wrong on that. I just wanted to mention it in case anyone thought it may be related or the cause of this problem.

I know this is long winded, but I wanted to give as much info as I could. Something obvioiusly put such a drain on the system that it caused the bike to stall and left the battery dead. Whatever it is seems to be aslo keeping the system from recharging the battery, which by the way is only a month old, but I know that doesn't mean it still couldn't possibly be the problem.

I am thinking possibly a bad connection or a short?? The fuses aren't blowing or anything. The other possibilities I guess could be the battery, or the alternator. For some reason I just don't really think they are the problem and am kind of still going by the assumtion that they are alright. Maybe some of you will show me I'm incorrect in thinking that way, that's part of why I'm posting. I also wanted to know if there were any particular wires that are best to start with considering the symptoms. Any input is appreciated, I need all the help I can get. Does this sound to nay of you like symptoms that point to one place more than the other?

Thanks

 

[nabrams]

You should be seeing approximately 14.8 volts DC at the battery when the bike is at 5000 RPM. If not, then your charging system is faulty. See the stator papers in the garage section of this site.
Both GS450 bikes I've worked on had bad regulator/rectifier that were letting too much voltage through and boiling the battery. A Honda I worked on recently had a bad R/R (but NO voltage was coming through it) and rotor - and just now the right coil died.
Fix that loose wire.

 

[Anonymous]

A bit of updated info. I noticed if I get the bike started (via battery charger) if I have the headlight off and turn the blinkers on they seem to blink at the correct speed. As soon as I turn the headlight on the blinkers stop blinking and the bike starts to want to stall. I tried turning the headlight on by itself, no blinkers, and had the same results as far as the bike wanting to stall. Could it be as simple as a short in the headlicht mabe, or does this point me in some other direction?

 

[earlfor]

The main ground wire on your battery is connected to a bolt on top of the transmission. If this connection is loose, you dont have any ground connection between your battery and the bike. If that ground wire is clean and tight, then either your regulator/rectifier or your stator (or both) are faulty. The stator is three phase AC. If one phase burns out/shorts out, the remaining two phases are usually enough to power the ignition and tailight and dashlights. Two phases do no provide enough power to operate the headlight or turn signals or starter and are not enough to charge the battery even if running only the ignition and dash/tail lights.
Two phases will maintain the battery. That is, when its dead and the starter just clicks, you can push start the bike and ride with the headlight off and limp home. You need to check the AC voltage between each of your three stator phases. Then check the DC output of your rectifier.

You should show (on a multimeter) 80 volts AC between each stator phase. The rectifier output as measured at the battery terminals should be between 14.5 volts and 14.8 volts. Both measurements are taken with the engine running at 5000 rpm.

Earl

A bit of updated info. I noticed if I get the bike started (via battery charger) if I have the headlight off and turn the blinkers on they seem to blink at the correct speed. As soon as I turn the headlight on the blinkers stop blinking and the bike starts to want to stall. I tried turning the headlight on by itself, no blinkers, and had the same results as far as the bike wanting to stall. Could it be as simple as a short in the headlicht mabe, or does this point me in some other direction?

 

[Anonymous]

Now that you mention the regulator, I noticed that the red wire coming out of it gets extremely hot when the blinkers or headlight is on. When they are of it is cool, turn either on and it heats up quickly to the point you can't hold it or you get burnt. Does that narrow it down some. I don't really have the experience to run the tests described in the above post, but I could I'm sure if told how.
Thanks

 

[earlfor]

The red wire on your regulator/rectifier is 12 V DC output and should go directly to your battery positive terminal. Headlight and turn signals are load.
All load is normally taken from the battery through a large red wire that powers up the fuse box. Charging output from the R/R going to the battery should not heat the R/R wire. Increasing consumption (turning on headlight) would cause heat in the power supply wire to the fuse box. Both these red wires look the same. Could you be mistaking one for the other?

Earl

Now that you mention the regulator, I noticed that the red wire coming out of it gets extremely hot when the blinkers or headlight is on. When they are of it is cool, turn either on and it heats up quickly to the point you can't hold it or you get burnt. Does that narrow it down some. I don't really have the experience to run the tests described in the above post, but I could I'm sure if told how.
Thanks

 

[Anonymous]

Ok, I have the right wire, but the wrong cause of it heating up. wWhen I turn the blinkers on I have to rev the bike to keep it from stalling. What is actually causing the wire to heat up is the revving of the bike. When the RPMs are up around 300 or so the wire gets very hot very quickly.

It has gotten fo hot that it has burned the clear plastic tube that covers the cooection and made it brittle and black. The connection itself is still good though.

 

[focus frenzy]

test your battery, it sounds bad.
clues are that the blinkers blink when the RPM is raised, this points that the charging system is working. at idle the charging system stock is borderline at best, and often the bike is using battery power to suplement the charging system output at idle as it can not supply all the power needed to power turn signals, headlight, brake light, and ignition.

if the battery is bad, you could jump off the bike and as long as the RPM is kept up it will run fine.

 

[Anonymous]

If there were a short bad enough to suck your system down to where the coils wouldn't work, I think for sure that would blow a fuse. But... if there is a short inside the battery, that would account for your symptoms. When you hook up a battery charger, does it make a buzzing sound? Do the charger wires get hot?

 

[earlfor]

Increased charging output from increasing revs is what is causing the wire to get hot. Once a wire has been heated enough to cause it to be brittle and the casing black, resistance is beyond specs even though it may look to be a good connection. The first thing you must do is replace that wire and the connectors. Youre pushing voltage through a short. dont run the bike until you have fixed that.

Earl

Ok, I have the right wire, but the wrong cause of it heating up. wWhen I turn the blinkers on I have to rev the bike to keep it from stalling. What is actually causing the wire to heat up is the revving of the bike. When the RPMs are up around 300 or so the wire gets very hot very quickly.

It has gotten fo hot that it has burned the clear plastic tube that covers the cooection and made it brittle and black. The connection itself is still good though.

 

[Anonymous]

Actually, if there is more resistance, there will be less current flow, and likely less heating, depending on the mechanism by which resistance has increased. A short is a circuit that doesn't pass through whatever it was intended to pass through, but instead goes directly to ground. An internal short in the battery will cause high current flow in the charging system, stealing output from the lights, coils etc., while heating the wire to the battery. The way to test if this is the problem, is to assess the load that the battery puts on a charger.

 

[Anonymous]

The charger makes a buzzing sound and the wires get hot when it is on "boost". The battery is almost new, so if it done for, I would think that something must have killed it. I can't seem to find any connections that seem bad aside from the one mentioned above. Good point by way, I should definately replace that wire, no matter what.

As far as ground wires go, where is the best possible place to ground them to, the frame, the motor, etc.?

I am trying to eliminat everything i can before spending money, at least the money it will cost me for a stator and regulator/rectifier, the bike only cost me $300.

I have a tester, but to be honest don't really know how to use the damn thing worth a s**t. I'd hate to spend $300 on parts to find out I just ended up ruining those also, and the bike still doesn't run and I'm back to square one.

Are there any connections I can eliminate looking at in trying to narrow down what it might be. I other words, do I have to trace down EVERY wire on the bike,k or are there some that should just not relate to the issue that I can bypass?

 

[earlfor]

The maximum charge rate for a 12 amp motorcycle battery is 1.2 amps. If you have been charging it or trying to start the bike with the charger on boost, it is highly likely you have destroyed a new battery and possibly fried various electrical components on the bike.

You may jump start a motorcycle from a car battery, but the car cannot be running because the car's alternator will destroy the bike's electrical system.

Earl

The charger makes a buzzing sound and the wires get hot when it is on "boost". The battery is almost new, so if it done for, I would think that something must have k
illed it.

 

[earlfor]

I cannot think of an instance relative to wiring where increasing resistance would decrease heat. Would you give an example?

Earl

Actually, if there is more resistance, there will be less current flow, and likely less heating, depending on the mechanism by which resistance has increased.

 

[Anonymous]

I'm sorry, but this is not really the case. A (12v) motorcycle system runs at 13.8 - 14.6 volts, or thereabouts, just like a car. Having the car running won't hurt anything. Regarding resistance, I=E/R where I=current, E=voltage, and R=resistance. You can see that, as R goes up, I must go down. This means less current at higher resistance. Since energy (watts) = current times voltage, this means that the circuit (the wire, in this case), is dissipating less energy, therefore, less heat.

Hope this helps.

 

[Anonymous]

No, actually I am thinking about it all wrong. My contention would be true if the wire in question set the total resistance for the circuit. As the current through the circuit is determined by other components, you are right. Resistance in the wire will heat it. Too many years, and too many beers! :roll:

But I am certain that automotive and cycle electrical systems are compatable.

 

[earlfor]

Having the car running puts you in the position of having two charging systems charging the same battery. The 100 amp output of the car alternator is going to fry the bike battery. Maybe in theory, you can do this, but in practice, I can say youre going to be very sorry you did.
I have never seen a charging circuit with two alternators charging the same battery. Two batteries connected by jumper cables is one battery as far as a charging system is concerned.

I=E/R is perfectly clear. No problem there. I am interested in hearing your explanation of this.

With a corroded wire and increased resistance in the wire, if you apply a load to the wire (say a headlight), the headlight may have a consumption of 6 amps. It requires 6 amps regardless of the wire condition. Consequently, if the added resistance in the wire is equal to 3 amps, then the drain on the battery is 9 amps through the wire up to the point of resistance/corrosion. Its like a strainer, what goes through the strainer is 6 amps. The other 3 are converted to heat. I have observed a lot of wires melt their insulation off and turn yellow at the point of resistance. If device load/draw remains constant, then amperage must increase to overcome resistance. Heat increases. If this were not true, then no wires would ever burn up.

Earl

I'm sorry, but this is not really the case. A (12v) motorcycle system runs at 13.8 - 14.6 volts, or thereabouts, just like a car. Having the car running won't hurt anything. Regarding resistance, I=E/R where I=current, E=voltage, and R=resistance. You can see that, as R goes up, I must go down. This means less current at higher resistance. Since energy (watts) = current times voltage, this means that the circuit (the wire, in this case), is dissipating less energy, therefore, less heat.

Hope this helps.

 

[Anonymous]

That would be true if you hooked them in series. Of course, when jumping you are hooked in parallel. The amps available doesn't determine the flow, rather the ratio of voltage to resistance does. The fact that the car voltage is identical to the bike means that no more current will flow with the car up hooked than without it, when when the bike is running. In practice, I have jumped many bikes from a car, and have never had an issue.

 

[earlfor]

So you are saying it is OK to have alternators from two different vehicles charging the same battery simultaneously?

Earl

That would be true if you hooked them in series. Of course, when jumping you are hooked in parallel. The amps available doesn't determine the flow, rather the ratio of voltage to resistance does. The fact that the car voltage is identical to the bike means that no more current will flow with the car up hooked than without it, when when the bike is running. In practice, I have jumped many bikes from a car, and have never had an issue.

 

[schinae]

Jumping a motorcycle from a running car seems to be the cause of about 80% of the electrical problems we diagnosis and fix at the shop where I work. I wouldnt do it.