I have a charging system problem please advise

1991ST1100 said:

John and I did not do the dynamic test but I will check into how I can do that. I guess cut into the shrink wrap or poke a needle in... back later with more

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Ok more interesting voltage readings from all 3 VRR's
This was the dynamic test on all 3 yellow wires for all 3 VRR's

1st VRR the one I got today that looks like OEM but isnt. I cut into the yellow wires to get the readings and all 3 wires showed .60v at idle and 1.25v at 3000 RPM +- .01-05v This VRR has not been HOT one time but it is not showing to be charging either.
The battery reading at idle was 11.98v and at 3000 RPM 11.87v

2nd VRR is the old OEM and I only did the 3000 rpm test because it began to smoke and drip black junk. it read 6.11v on all 3 +- .01-05v
The battery reading at idel was 12.11 and 3000 RPM was 12.5v ,showing it was charging some.

3rd VRR is the 1st one I bought with heat fins not OEM. all 3 wires at idle showed 6.09 +- .01-05v and the battery voltage started out at 11.88 but I quickly went to 3000 RPM and all 3 wired read 6.40v +- .01-05v with 13.2v showing at the battery the fins were HOT after the short test.

Also, I tested the meter on my car and it read 14.11v so the meter is acurate, earlier in testing the 3rd VRR, it showed 15.5 volts as it did before but not on this test it was 13.2

OK, maybe then you DO have two duff OEM VRR's. Definitely the melting one is dead. Might as well throw that one out. The second OEM is not new, but used, so we really don't know if it is good or bad.

And now you have an output of 13.2 at the battery with the sftermarket VRR, instead of the 15+V you had earlier, which is lower than you should expect to see at 3,000 rpm.

I'm out of ideas.

Bush said:

OK, maybe then you DO have two duff OEM VRR's. Definitely the melting one is dead. Might as well throw that one out. The second OEM is not new, but used, so we really don't know if it is good or bad.

And now you have an output of 13.2 at the battery with the sftermarket VRR, instead of the 15+V you had earlier, which is lower than you should expect to see at 3,000 rpm.

I'm out of ideas.

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I called the Honda dealership in Dallas earlier and explained all of this and he said it was insane. Is there any sort of computer on the bike or just the VRR? I think I just have 3 bad VRR's. I will probably run all the dynaic tests again just to see what the results are on a new day lol with the battery recharged. Oh and one more think I failed to mention was that even on the fuse panel the headlight slot was reading 15+ volts before also and today with the newer VRR it was reading right around 12. I guess because it was not allowing the Alt to charge and the battery was just slowly draining from all of the testing. Anyway Thanks for trying

Bush said:

OK, maybe then you DO have two duff OEM VRR's. Definitely the melting one is dead. Might as well throw that one out. The second OEM is not new, but used, so we really don't know if it is good or bad.

And now you have an output of 13.2 at the battery with the aftermarket VRR, instead of the 15+V you had earlier, which is lower than you should expect to see at 3,000 rpm.

I'm out of ideas.

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I think you misunderstood the 13.2v reading was from the first non OEM VRR I bought see results #3., it has the heat fins, but yes I had been getting readings on that VRR at 15v+ even as high as 16v for a second or two. But the V readings on the new non-OEM VRR I received today was .60v on all three yellow wires at idle and 1.25v at 3000 RPM with battery readings at 11.98 idle and 11.87 at 3000 RPM So it appears the new VRR is bad and not allowing any charging and very low readings on the dynamic test. The VRR I first bought due to the smoking VRR is the one that put 13.2 v out at idle and 13.5 v out at 3000 RPM with yellow wire readings at idle of 6.09 and at 3000 RPM 6.40v on each yellow wire.
I will do all these tests again tomorrow, just to make sure.

At the risk of saying something stupid because I've never diagnosed a charging problem on the ST, aren't the yellow wires always the AC wires? Were you measuring them with the meter on ACV or DCV?

dwalby said:

At the risk of saying something stupid because I've never diagnosed a charging problem on the ST, aren't the yellow wires always the AC wires? Were you measuring them with the meter on ACV or DCV?

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Good point!! Forgot about that myself! That explains those really weird readings Jeff got. Time to start over on that test.

I'm pretty sure we did the dynamic AC test of the three yellow leads from the stator when we talked on the phone. Here's a link to a thread where the test is discussed:
https://www.st-owners.com/forums/showthread.php?84285-Alternator-Trouble
Start at poST #24 for that but the rest of the thread should be of interest also.

One other thought. If the stator seems to check out but the reading at the battery with the engine running shows there is no charging - maybe there is a break (or major resistance) in one or more of the yellow leads BETWEEN the red 3P and the white 6P (VRR) connectors. I know of one STrider that discovered that, almoST as an after thought, after checking everything else a number of times. FWIW

John :STOC: Ten Fifty Eight

dwalby said:

At the risk of saying something stupid because I've never diagnosed a charging problem on the ST, aren't the yellow wires always the AC wires? Were you measuring them with the meter on ACV or DCV?

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That is an excellent point, I was measuring on DC volts, but I am not sure they are AC

John OoSTerhuis said:

I'm pretty sure we did the dynamic AC test of the three yellow leads from the stator when we talked on the phone. Here's a link to a thread where the test is discussed:
https://www.st-owners.com/forums/showthread.php?84285-Alternator-Trouble
Start at poST #24 for that but the rest of the thread should be of interest also.

One other thought. If the stator seems to check out but the reading at the battery with the engine running shows there is no charging - maybe there is a break (or major resistance) in one or more of the yellow leads BETWEEN the red 3P and the white 6P (VRR) connectors. I know of one STrider that discovered that, almoST as an after thought, after checking everything else a number of times. FWIW

John :STOC: Ten Fifty Eight

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If there was a break we would not have read infinite resistance, right, or no because its between the connector and VRR?

The static and dynamic stator tests are done with the red 3P disconnected, on the stator side of that connector. The additional check of the leads between the other side of the red 3P and the VRR's connector is to see if the stator's AC current is reaching the VRR. Test all three yellow leads for high (or infinite) resistance.

John

This is an update to anyone interested. I am working towards doing the 40a Alt but I found a guy on ST-Riders Norm Keller, that says we can install a automotive voltage regulator along with an automotive rectifier. I might try this but currently working on funds for the 40A job. My mechanic tells me its 6 hrs labor @his $90 per hr labor rate thats $540. Where do I get the 40A alt? How much is it? I understand there are some special tools required?

Thanks again to all the replies and advice.
By the way I am still desperately in need of the right mirror blinker housing I have a new blinker but just need the housing.

Might be worth giving Norm's VRR fix a try first.

Here's one page that details the 40A conversion. ST-Riders has a thread on it too in their Archive of Wisdom.

http://koczarski.com/mmartin/Alt.htm

You might find a used 40A alternator on eBay, or from Don Cortez on this site, who breaks lots of ST1100's for parts. Look for him in the Vendor's section. You can still buy a new 40 Amper from OE parts outlets too. Partzilla price is $420.00.

Jeff, if you don't plan on adding a lot of aftermarket electrical loads to your bike, get the 28A working first. Its a lot less work, and cost.

With this kind of job you need to be methodical in your approach. Make sure all your connections are clean and tight throughout the path first. No sense throwing a new VRR into a corroded electrical path.

Bush said:

Might be worth giving Norm's VRR fix a try first.

Here's one page that details the 40A conversion. ST-Riders has a thread on it too in their Archive of Wisdom.

http://koczarski.com/mmartin/Alt.htm

You might find a used 40A alternator on eBay, or from Don Cortez on this site, who breaks lots of ST1100's for parts. Look for him in the Vendor's section. You can still buy a new 40 Amper from OE parts outlets too. Partzilla price is $420.00.

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Thanks Bush!

Bush said:

Might be worth giving Norm's VRR fix a try first.

Here's one page that details the 40A conversion. ST-Riders has a thread on it too in their Archive of Wisdom.

http://koczarski.com/mmartin/Alt.htm

You might find a used 40A alternator on eBay, or from Don Cortez on this site, who breaks lots of ST1100's for parts. Look for him in the Vendor's section. You can still buy a new 40 Amper from OE parts outlets too. Partzilla price is $420.00.

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But I have a question about Norms fix using auto regulator and rectifier. I would ask him but he is up awhile or I would ask him. I wonder if the automotive parts can handle what appears to be an over voltage from the alt. But I will be rechecking everything. Here in Lubbock Texas we even had some heavy rains last few days so that's kept me from doing anything. I just was thinking that since I have done static and dynamic test, doesn't that mean all these connections are good?

Hi Jeff,

Will try to answer your questions, but I would defer to Norm on his knowledge of the auto VRR idea. It would seem, from the tests that you have done and reported on, that your connections are good. However, since the job of the VRR is to regulate the voltage going to the battery, it appears that isn't happening (at least with the one that allows over 15V) and leads me to think you have missed a high resistance value somewhere in the wiring, which is causing the VRR to ask for more voltage to push the current needed for the battery charge.

The auto VRR idea should be quite capable of handling the alternator output, but if there is still a high resistance problem somewhere, it would act just the same as the bike specific model. Dwalby's suggestion is good and I would go as far to say that you need to unwrap ALL of the wiring going to the VRR and battery from the VRR and carefully inspect it for areas of possible breaks in a wire or corrosion.

We haven't talked about that 6P connector at the VRR have we? Where those wires enter the connector, you can't really see the actual wires because of the plastic connector, but corrosion could have invaded the wire(s) at the point where they are attached to their spades, inside the plastic piece. If you can get those spade connectors out (there is a tool made for that) to better inspect the wires, you may uncover something there. Those connections to the VRR do get quite hot and over time, that causes the metal connectors to discolour and corrode, which will move into the actual wire over time.

My bike is in the shop now and hopefully I will be getting the 40A alternator. I will let yall know how it went. It might be in the shop for 4-6 weeks.

Probably the best move at this point. With your time and patience at troubleshooting, with whatever help was offered here, it seems you have done as much as possible. Hope it goes well at the shop.

Just an update for anyone interested. I am now making preparations for my mechanic to do the 40A alt upgrade. I guess the only thing I might need advise on is how can we determine if the alternator was damaged from when it was backed into and slammed to the curb. I forget who but someone said it might have cracked some sort of coating on the windings causing a short. Thanks again for all the support and advice. I have contacted John Osterhius I believe he is the only one with the special tool that is required for the 40A upgrade? Norm Keller from ST Riders will probably help me to make sure I have everything together for my mechanic, so thanks again for pointing me to ST Riders website. If anyone has any tips or advice feel free to help. Thanks again for everyone's part in guiding me through this process.