Stator and wiring burn out ? - GS 550et 1980

[ukjules]

I had a winter off biking and just back from few months away. Bike was running fine before I went away !!
I left battery neg term off and battery ok still.

Issue:
I have isolated the issue and reason for this. Just wanna check if indeed do need another stator !!!

I put battery back on but made the mistake of wiring one of the regulator wires from reg to pos battery terminal (the rest were ok) not the neg terminal as it should be.

Bike started and I rode about two miles before it died. Had to push to roadside.

Battery dead and wouldn't even sound horn.
After inspection I noticed stator 3 wires burnt out and reg wire to pos terminal.

I had to bodge wires back together and bump start and got home.

Redid wiring and after charging battery bike starts.

Issues :
It doesn't seem to be charging and stator tests show results attached .

Gonna order a new stator as i.must have fried it !!

What's think ? And are my tests correct ?

20240508_112310.jpg

[ukjules]

P.s I am sure I have asked before and with similar test results from test 1&2 with a new stator on my gsx250 all was good again.
It has to be the stator why on charge test voltage not increasing with revs ?

[Grimly]

If you're getting any resistance reading to ground on the stator wiring, it's knackered. There's an internal short to earth.
This is also shown by the low output on AC, with the stator disconnected.
You never know, though. Take the side cover off and have a careful look at the connecting loom inside, it's not unknown for an internal short to earth there. Much easier to fix than one in the stator itself.
Other than that, it's new stator time, imo.

[ukjules]

Understood..What a damn fool error I made.
All this and weather is biking weather in UK.
M&p stator 62£ and gasket 11£
And a whole lot of time wasted .... Hate doing this job

Thanks for.info ! Will do checks as stated and report results with working stator

[ukjules]

Stator arrived - awaiting gasket.
Bench test on new stator :

Res between 3 wires a-b,a-c,c-a
0.1-0.4ohms
Res each 3 wires to body of stator
1 or OL
(Basically the same.as my gsx250 one in situ in gsx250)

So all good so far ......

[ukjules]

Update : not good !! But today fitted new stator

Status of as was with old stator :
- when bike cold two tests seemed to show it to be ok. It failed when I had warmed bike up on 3 wires to earth.
- checking regulator it tested ok This testing with the diode setting on MM.

Current status:
New stator fitted which I bench tested to work.
Same regulator

= Bike if course starts fine but not charging . No increase in voltage on battery.

So:
Of the three elements that were in bike when I wired incorrectly the regulator and blew the stator wires ate
Stator - renewed
Regulator - not renewed but bench tested ok
Battery - holds at 12.8v and starts bike fine. Fully charged.

So I have to assume somehow the regulator is blown ? I will see if I have a spare and test this theory and report.

P.s the stator did look blackened so I reckon reg and stator somehow blew

[ukjules]

Updatw

Battery - same battery does accept charge from another bike. (GSX uses same battery and tested on that)
So battery ok
New stator

So it's just the regulator now. I have a spare but
On test on diode setting it checks ok but low figures 390. Sure they usually are ,,550-650

[ukjules]

Will fit anyway and see and report .
GSX one prob too small to test with ? Madly small one .

[Rich82GS750TZ]

Seem to recall your earlier threads with similar issues:

https://www.thegsresources.com/_forum/forum/technical-forums/electrical-ignition/91105-battery-not-charging-gs550e-1980

and this one:

https://www.thegsresources.com/_forum/forum/technical-forums/electrical-ignition/90637-regulator-3-wires-always-show-heat-issue-where-join

Seems to me, you could put in a new stator, correctly wire in a used SH-775 R/R, along with a known good or new battery, and enjoy years of trouble-free charging like so many of us. You've been advised to do this before, by several members. Or, you could keep testing and trying to figure it all out yourself. Good luck.

[slayer61]

Update : not good !! But today fitted new stator

Status of as was with old stator :
- when bike cold two tests seemed to show it to be ok. It failed when I had warmed bike up on 3 wires to earth.
<snip>

Do I understand you correctly that you ran the bike until it got warm with the 3 stator wires shorted together and held to ground (earth)?

[ukjules]

There are so many replies that have nothing to do with this problem best leave it to me. The issue is as per the start of this thread. I can't explain it again.

As for being 'told' to buy a mega regulator that will fix all my issues that is of no use to me. It has nothing to do with this thread. I have never bought one in 40 years ! And never will either !
I am totally conversant with testing if a bike is charging.

But for my own amusement I will note down the fix and analysis.
- I am now down to the regulator as it cannot be anything else after (one more time ) WIRING THE NEG LEAD FROM MY PERFECTLY WORKING REGULATOR TO THE POS BATTERY TERMINAL AND RUNNING BIKE FOR A MILE)
This as I stated blew the stator wiring ! and since then it won't charge !

Since then the bike will not charge. Even with new stator and working battery tested to charge on another bike.

Wemoto for a regulator and I'll inform if it works.
It has too as it is not wear and tear but me destroying the charging system !!

Seems logical that what I did broke both stator and regulator.

[ukjules]

Ok new regulator fitted and no change.
Bike will not charge but otherwise runs fine.

New reg bench test shows as faulty ?

It is either a faulty reg again or some wiring which can only be from the positive reg connector to bike as that's only wiring that is not renewed with a stator / reg renewal.

At a loss now to understand what has broken.

- replacement regulator coming
- will remove the GSX reg and test with that as I know it works .

Never seen this before a bike failing the most basic test of when increasing revs the voltage on battery increase. It remains the same or goes lower .

[ukjules]

Ok - took regulators to test on GSX.
I'll test the GSX one on the GS later . The GSX one I know works.
No reg has worked so far in GS since I wired the original regulator neg to the POS term of battery and blew the original stator wiring.

BUT
On GSX tests of regs as follows :

GSX regulator - works fine charges at just under 14v. I run this bike and no issues at mo. I'll take this to the GS later and test.

Original GS reg when I burnt out wiring - this charges at 16v on gsx but without the sense wire attached . So an odd result but shows charge where it doesn't on GS . No increase with revs on GS so it's looking like not reg ?

New regulator that bench tests faulty - this charges ok on gsx at just under 14v on GSX. Zero increase in voltage on GS.
I am getting a new reg as this tests odd in one of tests. Attached in previous posting.

Test details attached .

(One other reg I had in storage which I assumed was bust was. Displayed no charge on GSX.)

What on earth is wrong ?
Where does the positive wire go from regulator in the loom ? Could this have blown ?

This is no maxing out.my knowledge. What has blown to cause this ,?

[ukjules]

And finally I have same as battery volts at the regulator loom cable. 12.6v. the wire that goes from loom to reg.
(Then the 3 stair wires and reg earth cable)

So it's.not the regulator, stator (although prob was as blackened and tested bad when warm) , fuses.
Bike was perfect running order right up until I reached the battery after being away. Reattached the wrong reg lead to pos terminal.

That's the max I can go so bike back to storage as can get no further . All because I made one mistake wiring reg wire to pos terminal battery.

[pdqford]

UKJULES, on your 1980 GS550, is the rectifier separate from the regulator? If I read the GS550 service manual and wiring diagram in the manual (see BikeCliffs web site) correctly, they appear to be separate units. Pages 124-129 explain how to test each unit of the charging system, including testing of the diodes in the rectifier.