R/R blows up the bike? or vice-versa?

[marcrules]

Hello wise & mighty GSers!

1982 GS300LZ. Riding home and headlight filament went out, rode rest of ride home w/ high beam (about 5 miles). Next day, started it up to go get a new head light, rode for about 2 miles, and engine began cutting in and out rapidly. High beam filament blew, speedo light went out, left turn indicator stopped indicating, left front blinker bulb blew (and left side rear blinker stopped working), tail light bulb blew (and brake light stopped working), high-beam indicator light stopped working.

Examined wiring diagram, and all of these components that stopped working/blew have B/W wire in common, which I believe is a negative/ground wire. I don't know if this is relevant. Also, the fuse was toasted, but had not blown (single 15A fuse on this bike).
Ordered a new headlight, replaced the fuse and headlight.

Went through all the connections, cleaned everything and replaced a few that were particularly bad. Did not find any melted/frayed/bare wiring, though I did not unwrap the harness (I did take care of a lot of corrosion at some of the terminals). There is no continuity between the B/W wire connector of the instrument panel and the components in the instrument panel where there should be, so I think something in there is fried, too.

Went through the stator papers. Good Battery. Battery was getting 16v when engine revved. Stator checked out perfect. R/R most definitely did not check out; I'm pretty sure it is fried. (Note: engine did not do the cutting in-and-out thing while idling/revving during all of the testing, and the fuse and headlight stayed good).

Questions: did one of the bike components/wiring go bad and fry the R/R? or did the R/R go bad and fry the above-mentioned components? Should I replace the blown bulbs and the R/R and see what happens, or is there something else I should look for before I risk frying a new R/R?

Any input would be greatly appreciated. Thanks for reading. And many thanks to the many posters who have already unknowingly helped me out!

P.S.: PO reportedly replaced the R/R about two years ago.

[cowboyup3371]

At what RPM was it pulling 16v? That, based on what I was told, is way too high but maybe one of the other electrical gurus can help out more so than me.

BTW, welcome to the site. What part of Portland? I have family in Vancouver and down in Salem.

[bonanzadave]

16vdc will boil the battery. You may have lost the RR ground. Find that ground point, clean it up good and then run a dedicated ground from that point to the battery neg post. Re-check the charging voltage. My guess is the same as yours. The RR is toast.

[Redman]

16v is too high, and can burn out bulbs quickly.

Either the R/R has failed
or
THe R/R is not well grounded. Look for the black wire on the R/R, it should be grounded somewhere. On the bikes I am familiar with (850G & 1100G) that black wire is connected to the battery box with a ring terminal under the mounting bolt of the starter solenoid, along with black/white wire from wiring harness. And that back/white wire goes thru the wiring harness and other back/white wires are spliced into it and it also is suppose to be grounded to the frame someplace (underseat, by frame near top of battery) but sometimes that connection is not good, and then the R/R isnt well grounded.
You have a volt meter, good, so you can check this out (and I think it is one test described in the stator papers). Find that black wire from the R/R and see where it is connected (that starter solenoid bolt), and then with bike running check for voltage between that point and battery negitive. It should be about zero. Maybe you might find it to be 1.5 or 2 volts, I quess that because you said you measured 16 volts at battery and that is 1.5 or 2 volts too high.
THis is why folks recommend adding your own "ground" wire from that place on the battery box directly to battery negitive.

Most all electrical operated devices on your bike will have a black/white wire on it.

>>later note.
Oh, BonanzaDave said about the same thing while I was typing.

(have you noticed that if someone calls it "typing" that also means they are old and type slow.)

.

[850 Combat]

If you had found and repaired the corroded connections a day earlier, the R/R may not have failed. +2 on adding the grounding jumper between the R/R ground and the battery.

[marcrules]

There is a b/w wire from the r/r, the negative, and out of the same bundle of wires, there is a b/w wire that attaches with a ring terminal at one of the screws holding the r/r. That connection was completely corroded, and I had to wirebrush off a layer of rust/crud. If that is the r/r ground, than I suspect Redman and bonanzadave are right, and the r/r lost the ground. I did all the testing after cleaning that connection, so I still think the r/r is fried. I plan on replacing the r/r and wiring a ground from that spot directly to the negative battery terminal, as Redman and bonanzadave (& 850 Combat) suggested. Thanks for your responses!

So I take it that it makes sense that the r/r would lose the ground, which would fry the r/r, and then a succession of components in the circuit connected to the same b/w wire? Is that because there is too much voltage coursing through the circuit after the r/r is gone?

cowboyup: I'm not sure the rpm when it was pulling 16v, b/c this bike has no tach. I would estimate it was about 4-5k. The voltage just kept climbing as I revved it, and I didn't want to push my luck.
I live in SE portland, pretty close in. Anyone in your family have a stockpile of unwanted r/r's? :-)

[bonanzadave]

Anyone in your family have a stockpile of unwanted r/r's? :-)

Duane (Duaneage) is the RR guy around here.

http://www.thegsresources.com/_forum/member.php?u=208

[BassCliff]

Greetings and Salutations!!

Hi Mr. marcrules,


I'm just going to dump a ton of information on you. Let me share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Redman]

...
....
So I take it that it makes sense that the r/r would lose the ground, which would fry the r/r, and then a succession of components in the circuit connected to the same b/w wire? Is that because there is too much voltage coursing through the circuit after the r/r is gone?...
....
....:-)

Yes and no, mostly No.

If the R/R is not well grounded, the R/R can not do what it is suppose to, even if the R/R itself is okay.

If the R/R is not well grounded, then the R/R can not regulate at all or regulates at too high a voltage (at the battery anyway), the voltage output is high and the high voltage can burn out light bulbs quickly (not because are on a b/w wire, but because the battery voltage is too high) and "boil out" the battery over time. BUt no, that doesnt fry the R/R.

Your ground wire from the R/R may be making good connection to the battery box (at R/R mounting bolt or solenoid mounting bolt), but the battery box itself may not be well grounded, which is why that b/w wire from the wire harness also connects to the battery box, but sometimes even that isnt good enough.
Again, why it is suggested to measure voltage between the R/R ground/negitive wire and the battery negitive.
Again, why folks recommend adding your own ground wire from there to battery negitive.

SO that is one thing to look into further. And in addition to looking visually, check it with a volt meter. SHould be zero volts - nauta - nuffin - zippo between the R/R ground wire and the battery negitive with engine running at mid-RPMs.

Other thing is that the R/R could be bad.

And .....
And sometimes when the R/R fails, depending on how it fails; it can burn out that b/w wire in the wiring harness. And sometimes when a R/R fails, depending on how it failed; it can burn out the stator.

SOunds like you are doing good.

Also note that all the b/w wires are all be connected together, well, the other end of each b/w wire that you see are all connected together inside the wiring harness.

.

[marcrules]

Thanks, Redman.
After following the stator flow chart and performing the continuity checks shown in the manual, it looks like the r/r failed.

If improper grounding didn't cause the r/r to fail, what might it have been? I know it is a common problem for GS models, but is it merely bad connections and age? Bad r/r component? or something about the way the GS is wired? I would love to prevent another r/r failure/incident described in my original post.

I fear the next trick will be unwrapping the wiring harness to make sure the r/r failing didn't burn out the b/w wire along with half the rest of the electrics. Is there a way around this?

[posplayr]

Thanks, Redman.
After following the stator flow chart and performing the continuity checks shown in the manual, it looks like the r/r failed.

If improper grounding didn't cause the r/r to fail, what might it have been? I know it is a common problem for GS models, but is it merely bad connections and age? Bad r/r component? or something about the way the GS is wired? I would love to prevent another r/r failure/incident described in my original post.

I fear the next trick will be unwrapping the wiring harness to make sure the r/r failing didn't burn out the b/w wire along with half the rest of the electrics. Is there a way around this?

Follow the GS Charging System Health thread at the bottom of my signature to improve your R/R and Stator chances of survival.

[marcrules]

*update*

Installed one Duaneage-supplied Honda r/r (a steal), sense-wire to tail light and wired extra ground straight to battery terminal (per the geniuses here at gsresources), cleaned/replaced every connector, replaced all the bulbs that had blown, and my little gs is up and running! (yes, I do want a bigger one).

Beats riding the bicycle to work.

Thank you Duanage / posters / gsresourcers!

[Flyboy]

Good to hear you got it fixed up and are mobile again.
This place is a treasure trove of information, beware, it is highly addictive.

[posplayr]

Installed one Duaneage-supplied Honda r/r (a steal), sense-wire to tail light and wired extra ground straight to battery terminal (per the geniuses here at gsresources), cleaned/replaced every connector, replaced all the bulbs that had blown, and my little gs is up and running! (yes, I do want a bigger one).

Beats riding the bicycle to work.

Thank you Duanage / posters / gsresourcers!

Unless you are fastidiously clean with maintaining all the contacts from battery to taillight, the undelined item above will cause overcharging.

Here is another recent link with a bewildering sets of experiments before coming to this conclusion.

http://www.thegsresources.com/_forum/showthread.php?t=168352

The ultimate solution for the sense wire is either direct to the battery and suffer the current drain issue, or wire in a coil relay mod and use the output as a sense point.

As far as electronics failure:

There are 4 primary factors:
1.) vibration induced fatigue failure
2.) thermal cycle induced fatigue failure
3.) Elevated temperature stress
4.) voltage spike stresses

The R/R is subjected to these, but also due to the shunt design is much more susceptible to self heating. The operation of the shunt regulators goes hay-wired when the connections between the R/R and the battery are not low impedance. Among other fault conditions, when there are poor connections the power can not be pushed from R/R to the GS electrical because of the voltage drops to the battery (the Regulator operates to control voltage). The result is the power is shunted back to the stator stressing both until one or both eventual fail due to the additional high current and higher thermal stresses.