I have a charging system problem please advise

1991ST1100 said:
What is the yellow wire mod?
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this is getting rid of the red connector that joins the three yellow wires that come from the alternator before it goes to the voltage regulator. Instead of relying on the connector, one solders each yellow wire to the mating yellow wire on the other side of the connector.
With respect to your voltage regulator getting hot. The unit is doing a number of things.
1) it's converting AC current from the alternator to DC current
2) it's regulating how much voltage is required to charge the battery, and dumps the extra current that isn't needed to a heatsink. That is what the fins do as well as the frame to which the unit is bolted to.
The goal is to make sure that you have good connections in the charging system. What happens over time is connections get loose which leads to sparking that in turn can heat up wires and melt connections as well as the insulation around the wire.
Corrosion also comes into play. The wire is stranded, and when strands of wire become corroded it no longer allows the current to flow through those strands and the good strands take on the load and heat up. If the current can't flow from the alternator then it can burn the windings.
I don't think you have to change the battery every two years, depending on the quality of the battery they can last up to 7 plus.
As you say you don't know the history of the battery so best replace it. (sometimes there's a letter code on the side and this can inform a dealer when the battery was manufactured)
The thing is, the 28 amp alternator is a good design. It does the job well, as long as you keep the accessories to a minimum and check the charging systems connections. Make sure the terminals on the battery are clean and tight.
Let us know what the voltage is with the new battery installed at 3000rpm.
 
Just for your further information - the VRR will normally become very hot to the touch - too hot to touch actually. That is why Honda chose to mount it onto that massive slab of aluminum, which acts as a heat sink for it.
 
It was so hot that, the original VRR not having heat fins, it was literally spewing ALOT of smoke, from melting the black stuff thats on the original VRR. That indicates a bit too much heat I am fairly sure. I assumed the VRR was fried but maybe not. I bet there is a way to test it with a meter. Thanks again for the the advice! I will let everyone know how it goes after get the new battery.
 
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I have the manual but I am not a great mechanic and its a bit confusing. Thanks for the flow chart! I will be getting a new battery next week I hope and will let everyone know how that goes.
 
Today. I replaced the battery with a new Yuasa YTX14 - BS. Charged it properly and put on the bike today and still have an overcharging problem. The voltage reading across the battery terminals with the bike running at idle speed 1000 rpm was 15.85v - 16.05v Is this so much voltage that it will cause the VRR to get so hot I can't touch it within 2-4 minutes? Maybe I do not even have a problem? or is 15.85v way too much?
When revving the engine to 3000 rpm it mostly stayed at 15.85 but did go to 16.05v for a moment. I will now be going back through all of your posts to work through all possible solutions. Sorry it took so long to get the new battery installed. I searched and searched and finally found the best deal at Summit Racing for 68.97 and did'nt pay shipping because they ordered my headlights from another company and included that in my order. http://www.summitracing.com/parts/ysa-ytx14-bs
 
kiltman said:
this is getting rid of the red connector that joins the three yellow wires that come from the alternator before it goes to the voltage regulator. Instead of relying on the connector, one solders each yellow wire to the mating yellow wire on the other side of the connector.
With respect to your voltage regulator getting hot. The unit is doing a number of things.
1) it's converting AC current from the alternator to DC current
2) it's regulating how much voltage is required to charge the battery, and dumps the extra current that isn't needed to a heatsink. That is what the fins do as well as the frame to which the unit is bolted to.
The goal is to make sure that you have good connections in the charging system. What happens over time is connections get loose which leads to sparking that in turn can heat up wires and melt connections as well as the insulation around the wire.
Corrosion also comes into play. The wire is stranded, and when strands of wire become corroded it no longer allows the current to flow through those strands and the good strands take on the load and heat up. If the current can't flow from the alternator then it can burn the windings.
I don't think you have to change the battery every two years, depending on the quality of the battery they can last up to 7 plus.
As you say you don't know the history of the battery so best replace it. (sometimes there's a letter code on the side and this can inform a dealer when the battery was manufactured)
The thing is, the 28 amp alternator is a good design. It does the job well, as long as you keep the accessories to a minimum and check the charging systems connections. Make sure the terminals on the battery are clean and tight.
Let us know what the voltage is with the new battery installed at 3000rpm.
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This has been one of the biggest Honda problems since the CB750 came out. Corrosion or looseness at the alternator pigtail. Two of my three GL1000's had this problem...which I suppose is why I got them so cheap. My first had melted plastic the connector. Found this on my new project inspection routine. Lots of green corrosion and obvious arcing damage. The alternator was not damaged. Replaced the pigtail and connector with a waterproof connector for a boat trailer. Soldered the wires, didn't bother with crimps. No more problems. My next had the same problem but the stator was burned also. Replaced it and the new pigtail with another trailer connector.

It's easy to ignore inspections under the plastic cowls. Take all your connectors apart, inspect for dirt, oil, corrosion or indications of poor contact. Clean with contact cleaner and lube with dielectric grease. Do it at least annually...more often if you ride in the rain or live in a high humidity region.
 
1991ST1100 said:
Today. I replaced the battery with a new Yuasa YTX14 - BS. Charged it properly and put on the bike today and still have an overcharging problem. The voltage reading across the battery terminals with the bike running at idle speed 1000 rpm was 15.85v - 16.05v Is this so much voltage that it will cause the VRR to get so hot I can't touch it within 2-4 minutes? Maybe I do not even have a problem? or is 15.85v way too much?
When revving the engine to 3000 rpm it mostly stayed at 15.85 but did go to 16.05v for a moment. I will now be going back through all of your posts to work through all possible solutions. Sorry it took so long to get the new battery installed. I searched and searched and finally found the best deal at Summit Racing for 68.97 and did'nt pay shipping because they ordered my headlights from another company and included that in my order. http://www.summitracing.com/parts/ysa-ytx14-bs
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I think the voltage output is too high...unfortunately I don't have my shop manual with me. If I recall correctly the range for the 28amp alternator is between 14.4 and 15.1 anything higher could be interpreted as an issue. You have an aftermarket VRR with fins I think those were used on the police model....on the off chance unbolt the VRR and see if there's a protective film still on the back, if so remove the film. The other possibility is that it's the wrong VRR... I'm grasping
I ordered one from ebay and it was a Chinese knock off for $25 delivered it worked within spec, that price is kinda worth it to rule out the VRR as a problem
 
Oldbikefixr said:
and lube with dielectric grease.
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I used to do this but have since learned that you're supposed to use the stuff on the outside of the connectors to keep water out...not packed into the connectors where it acts as an insulator. Maybe best to use on spark plug boots, if at all.
If you're looking to prevent corrosion on contacts, dielectric grease isn't the answer.
There's controversy about this. We don't need dielectric grease so why not leave it alone.
 
DeanR said:
I used to do this but have since learned that you're supposed to use the stuff on the outside of the connectors to keep water out...not packed into the connectors where it acts as an insulator. Maybe best to use on spark plug boots, if at all.
If you're looking to prevent corrosion on contacts, dielectric grease isn't the answer.
There's controversy about this. We don't need dielectric grease so why not leave it alone.
Click to expand...

I have been preparing connectors like this since 1962...numerous restorations/rebuilds and never had a problem. It does inhibit the return of corrosion. Just be sparing with it. My region is northwest Louisiana and northeast Texas....cool to very hot, dry with one very rainy season. If you operate in an area of low humidity, you certainly don't need greasy stuff...just inspect occasionally. My main areas of concern are the connector on the alternator pigtail and any connectors that can get soaked when washing the bike or riding through rain or standing water.

There are downsides (to anything).
If you live in dry, dusty areas...guess what the grease attracts and retains? You can catch this with periodic inspections...just clean and reapply. The crud remains on the outer surface of the grease.
If you have a poor connection, grease may isolate it. After cleaning the contacts, look for evidence of that...usually the lack shiny areas where contact between the male and female connectors either do or don't touch. Give the male connectors a little twist or slight bend until positive contact is restored.

Whether or not you agree with using a grease, check your connections with a frequency appropriate to your environment. Kill the green fuzz and ensure you have positive contact.
 
Oldbikefixr said:
This has been one of the biggest Honda problems since the CB750 came out. Corrosion or looseness at the alternator pigtail. Two of my three GL1000's had this problem...which I suppose is why I got them so cheap. My first had melted plastic the connector. Found this on my new project inspection routine. Lots of green corrosion and obvious arcing damage. The alternator was not damaged. Replaced the pigtail and connector with a waterproof connector for a boat trailer. Soldered the wires, didn't bother with crimps. No more problems. My next had the same problem but the stator was burned also. Replaced it and the new pigtail with another trailer connector.

It's easy to ignore inspections under the plastic cowls. Take all your connectors apart, inspect for dirt, oil, corrosion or indications of poor contact. Clean with contact cleaner and lube with dielectric grease. Do it at least annually...more often if you ride in the rain or live in a high humidity region.
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Is anyone willing to call me about the issues I have in figuring this out? I have questions from doing the alternator test from the repair manual, did it fail, did it pass, I do not know. Please call and help me by phone. Jeff 806-777-2485 is my cell phone, call anytime til 10 pm central time. Thanks
 
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No one has called me yet. If someone can call and help please do. Here is what I have done so far. New battery installed after proper charging and it is a Yuasa YTX14 BS. Prior to the new battery I installed a new VRR voltage regulator rectifier and it is not OEM and has heat fins in it. The VRR is still getting very hot to touch. The voltage read at idle was 15.8 to 16v same at 3000 RPM.
I did the alternator test on the 3 pin red connector and I have many questions about this test. Its on page 16-6 of my Honda service manual. Please call me anytime before 10pm central time. Thanks Jeff 806-777-2485
 
Good to talk to you, Jeff. Glad I could help walk through checking the windings. At this point I'd borrow another VRR and see if you simply have a faulty aftermarket VRR.

John
 
John OoSTerhuis said:
Good to talk to you, Jeff. Glad I could help walk through checking the windings. At this point I'd borrow another VRR and see if you simply have a faulty aftermarket VRR.

John
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Thanks for taking time to call me John. You were very helpful with the alternator test.
 
I have a new update on the progress of my charging system problems. I have done almost everything that everyone has advised with the exception of checking the wires coming off the alternator. This evening I took off all the side covers, and from the left side I can see the alternator and a wire. I ran out of time to continue working on it but soemone please tell me what an oil leak can do to the alternator. there is alot of oil and grease built up on the wire that is accessible from the left side and it has a rubber cap that was not on it and just hanging there covered in oil and dirt. I am hoping the alternator is sealed and that only oil has got into the wires. Any tips and advise on this is greatly appreciated and you are welcome to call me also Jeff 806-777-2485 anytime til 10 pm central. Thanks
 
Your 28 amp alternator is actually oil cooled, so no worries there. What you have is an oil leak FROM the alternator, where the wires enter. That seal has been a problem area for many pre '96 ST1100's.
 
Bush said:
Your 28 amp alternator is actually oil cooled, so no worries there. What you have is an oil leak FROM the alternator, where the wires enter. That seal has been a problem area for many pre '96 ST1100's.
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One of the tips given as a solution to help fix my problem of over charging was to check the pigtail wires coming off the alternator. I do not understand an oil cooled alternator but I would think that oil saturated wires could be a problem?
 
John OoSTerhuis said:
Good to talk to you, Jeff. Glad I could help walk through checking the windings. At this point I'd borrow another VRR and see if you simply have a faulty aftermarket VRR.

John
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Where would I borrow a VRR? Also I think the old VRR is actually working but it begins to smoke when the engine has run long enough to heat it up, 3-5 mins aprox
 
1991ST1100 said:
Is anyone willing to call me about the issues I have in figuring this out? I have questions from doing the alternator test from the repair manual, did it fail, did it pass, I do not know. Please call and help me by phone. Jeff 806-777-2485 is my cell phone, call anytime til 10 pm central time. Thanks
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Hey oldbikefixr
I am still a bit confused about where the pigtail you are talking about is located. Sorry I dont even know what a pigtail is. You are welcome to call It seems you might be able to help. Thanks
 
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