electrical help needed

[Jonesy :-)]

Just before I go any further can someone confirm the following test is good or bad result
when I put the meter in beep mode and check the wires for the alternator at the plug behind fuses I get beeps from one white wire to the other, or continuity between the phases........I'm hoping you'll say that's wrong.
I also got both ends of each white wire in the harness and got continuity. without getting beeps from any of the other pins, tells me they aren't touching or melted together in the harness

[excess.11]

No point in carrying out any changeover of components if there is suspect melted /overheated wiring in the loom.
No need to do the stator until we can sign off on the most likely culprits..the wiring loom and reg/rec unit.
Do the loom first............ and then use the reg/rec from your spare bike.......I understand your concerns.....but unless we are using new or known working items we can t proceed to the next step....or find out if we have eliminated the problem.

[Jonesy :-)]

I'm really loathe to use good rec/reg from my "working" bike in case I fry it, I'm going to replace the stator from ute load of spares and see what happens
fkn electrics!

[excess.11]

Jonesy...I was under the assumption the melted wiring was from the alternator .First up........don t use the spares you ve described.............use the known working ones off your spare bike............we DO know from what you ve told us...this bike is charging and running ok.
 We can t find the fault if your not using known working or new parts as replacement.
 In this case......get the "if it ain t broke" mentality" a miss.....
In my experience....components can show a pass on a test not in circuit.......ie a bench test with multimeter under no power........but can / will fail when under power with a load....and can be intermittent due to hot connections or failing components from age or distress..
You need to ascertain there is no further damage to the wiring harness which had the melted connector. As both myself and Miti have explained this needs an examination of the copper conductors leading back from the burn t connector...not only with those melted........but also the other wires in that part of the loom. Cut the outer wrapping of the loom to visually check this.
Once you have done this and are satisfied........ remove the known working rec/rec unit from the spare bike and install this unit.

[Jonesy :-)]

Thanks for all the additional info fellas, a lot to digest there
just want to rewind and go back a bit to answer Jeff's question
The wires I'm looking at replacing are melted in the main harness, not from alternator to plug behind fuses.
Both the spare rec/regs I tested are form the "ute load of spares" I acquired a while back, not from my good running bike. (which will be a last resort to pinch bits from....if it aint broke etc)
I did resistance test on all 3 rec/regs on the bench and they all passed according to the book, (page 165 steps 4 & 5 attached in this thread) I got around 4 to 5 Mohms with meter leads one way and O.L with leads the other way (OL comes up with probes not connected to any thing also......high resistance?)
Then I followed step 3 on page 164 and got 1.2 to 1.3 volts on all 3 (another pass)
It was step 5 where they failed and showed zero volts on one and 18v on the other 2.

EDIT
where is this coil that the green wire is connected to? acessible? or inside the rec/reg?

[excess.11]

I believe from what Jonesy has indicated ......one of the reg/rec units is off his second bike which has no charging
 problems .  I have also got him to carry out the tests as per book on the unit already existing on the faulty bike....with a report those tests carried out are ok.
Unfortunately with out having a meg ohm meter  to test the insulation on the coils and wiring harness can t be conclusive ....maybe Jonesy needs to take the unit to an Autoelec to confirm on that.
The other most frustrating part is not being there in person to help out with the issue .

[Miti]

....but can be a little overwhelming for some. Pays sometimes to use the "Kiss" method to get where you want to go in dealing with electrical issues.

I'm right with you on that Jeff... I agee that my write-up is OTT, but just thought I'd put the whole brain-dump down in case just some of it helps out...

My own thoughts with Jonezy's bike is that he has a small collection of duff rec/regs... The dodgy alternator connector was a good find, but over-voltage is almost always the regulator as almost every other fault causes low output....  I would test the alternator coils as per the book and bang an known good rec reg on...

HTH

Miti

[excess.11]

Jonesy......to double check your changeover parts are ok.......either use the working ones from your spare bike that you have said are ok .......or check them on that bike as well.......... as you have said its charging system is ok. Without bending your mind too much on tech stuff this is the best way to locate the suspect component or to eliminate it as not being faulty .
Gotta agree xtian ........great write up....but can be a little overwhelming for some .
Pays sometimes to use the "Kiss" method to get where you want to go in dealing with electrical issues.

[Christian Raith]

XSellent write up Miti
Thanks for that.

[Miti]

Hi Jonezy.  Can I suggest that you go "back to basics on this..?  It's been a PITA for you for some time now...

BATTERY:  you MUST check electrolyte level prior to any testing... ONLY use DEIONISED water - NOT distilled...

A properly filled, fully charged battery, should read 12.6 Volts across the terminals.  Battery chargers produce anywhere between 13.6 - 14.2 Volts and a battery that's just been charged will read high, with the voltage decaying down towards 12.6 Volts when the charger is removed.  Less than 12.0 Volts indicates that the battery is past its best (not duff, just not at its best).

Cranking volts/amps are fairly subjective,  Different engines spin at different rates (age/wear/temp all play a part) so if the engine spins over OK, then don't worry.  If it doesn't, then measure across the terminals and check that the voltage doesn't go below 10 Volts.  This is because the TCI is only designed to fire down to 10 Volts... Lower than that, the  engine might spin, but the ign probably won't fire it up...

CHARGING SYSTEM:  You've already discovered some of the pitfalls of owning an aging bike... The alternator connectors are a problem for almost every large capacity bike over 20 years old (younger if it's a Honda!).  Replacing the connectors is a good idea, but ONLY if you can do it WELL... If in doubt of your skills here, DON'T do it... Get a PRO to do it...  WHY..?  The current available here can easily cause electrical fires.  Poor joints present as a high resistance and a current flowing through a resistance causes heat...  The heat causes the electrical pins to expand and loosen, causing higher resistance and more heat... So good joints are ESSENTIAL.

With regard to the damage to the wiring... I've seen MANY bikes with the alternator plug problem... The wiring damage is usually caused by the heat caused by the high resistance joint.  The plug normally suffers worst, then the insulation up against the pins, then the insulation further up the wires... You can normally see that the heat damage diminishes as you examine further up the wire.  The wire beyond visible heat damage is usually OK.

BTW: The damage isn't confined to the insulation... The heat causes the copper to oxidise with the air around it - look for the wire to turn from copper colour to red or black (depending on the alloy they're used in the wire).

ALTERNATOR:   The XS1100 item is one of the most rugged bike alternators around... It's a well made chunky bugger and it's normally mechanical damage (impact) that causes its demise...

It's got a 3-phase stator winding and a single phase field coil.  The field generated is "pulsed" to simulate phased field coils by the use of a shaped rotor between the field and stator coils.  This rotor spins with the crank and causes fluctuations twixt field and stator coils that cause majic elektrickery to work.

The elektrickery generates easily enough power for the systems aboard the XS1100 and the peak voltages available from each of the stator phases are approx 15 Volts (A.C)

Voltage regulation is conducted "at source" by turning the field coil on and off.  The voltage doesn't drop immediately to zero as the magnetic field takes a finite time to collapse (check out "hysteresis" on Wikipedia) so the regulating device gets an easy ride and normally lasts for decades....

REGULATION:  The XS1100 uses a Shindengen solid state rectifier/regulator.  The rectifier is a 3-phase, 6 diode device that operates independently of the regulator (even though they're in the same case).  The diodes are arranged into a "3-phase, full-wave bridge" that can produce a DC output of approx 18 Volts.

Inside the rec/reg case, the DC output produced by the rectifier powers a regulator that is, essentially, a voltage comparator.  It's factory preset to compare the DC output from the rectifier against 0 Volts (frame and battery earth).  If that voltage passes above 14.2 Volts (ish) the regulator turns the field coil off. (brown and green wires from rec/reg to field coil).  As the "system" voltage falls back down, the regulator senses this and turns the field coil back on... This happens many times a second, so the regulated output is a fairly stable DC.

TESTING:  Wiring is the obvious one... Check everything twice.  Especially "feel" the connectors you suspect... If they're hot and not against the engine, find out why they're hot! (corrosion, looseness, etc).  Also check ALL earth points:  Battery -ve to battery lead, battery lead to frame, frame to engine,  Harness to frame, rec/reg to frame.  On my own bikes I also add an additional lead between the battery -ve and the engine and I make 100% certain that the rec/reg bolts are clean and that the frame mounting points are paint and rust free...

ALL the available manuals have methods to test the alternator windings, field coil, and rec/reg.  It's not a complex system, but it helps to know what's being tested:

STATOR:  This comprises three coils of enamelled copper wire.  The ends of the coils are connected in  a series loop (like a triangle). Two coils join at each point of the triangle and the white wires connecting the stator to the outside world connect to these points too. (I'm ignoring the additional yellow wire as that's for lighting on certain models only and will only confuse the topic).

FIELD COIL:  This is another coil of enamelled copper wire.  One end is connected to the brown rec/reg wire, the other end is connected to the green rec/rec wire.  The rec/reg passes voltage through this coil and turns it into an electromagnet (TIP).

When you're testing these coils, you testing for a number of things:

That the coils aren't broken (resistance/continuity)
That the coils are properly insulated from each other (insulation)
That the coils are properly insulated from the engine (insulation)
That the coils are properly connected together. (resistance/continuity)

The alternator is usually the last thing that fails on the XS charging system... If the coils pass the resistance/insulation tests your alternator s probably OK.

REC/REG UNIT:  As I described earlier, the rec/reg is two units...  It's six diodes are arranged in a "bridge" comprising three series pairs, arranged such that each pair is connected in parallel.  The phase outputs from the generator connect to the middle of each pair.  The +ve DC output is developed at the cathode ends of the three pairs and the -ve at the anode ends.  When testing the rec you're check these:

That each diode passes current from anode to cathode (continuity)
That each diode doesn't passes current from cathode to anode (isolation)

This involves testing each diode, both ways, so it's 12 tests.

Regulator:   You HAVE to be sure that all the other parts are OK before you can test the regulator.  A fault in any of the other parts can fek up the regulator's operation...  Basically, it's tested by measuring the battery voltage with the engine running.  A good system will keep 14.2 Volts (d.c) across the battery at 3,000 rpm.

FAULTS:

Alternator faults are usually confined to LOW output.  A HIGH output fault won't be the alternator.

Rectifier faults can present in a few ways...

A single open circuit diode will present as a slightly low output...  The more open circuit diodes, the lower the output will go.  An open circuit diode in each of the pairs will mean no output...

A single short circuit diode will either:

Short the output from one alternator phase to earth and possibly burn out that phase of the alternator.
Short AC volts from the alternator to the battery +ve.  They don't like this, it tends to boil the battery ad plays HAVOC with sensitive electronics like the TCI and Tacho.
or - when not running
Shorts the battery +ve to one of the alternator phases... This can flatten the battery and can fry the stator phase coil, if there is an insulation fault (which is why we test for that first!)


TWO short circuit diodes in the rectifier will probably blow the main fuse as it'll short the battery +ve to the -ve through that fuse..

Regulator faults normally present in one of two ways:

NO charge output across battery - the reg isn't powering the field coil
Charge across battery WAY too high - the reg isn't turning the field coil off.

For the first, check all the field coil wiring and measure field coil continuity/insulation

For the second, place a spanner against the alternator cover.  If it's pulled on hard by the magnetism, the field coil is working overtime and the rec/reg unit will need to be changed...

For faults where the charge is a little high or a little low - test all the connections, then the units one at a time... BE CERTAIN that the part you've tested is OK, before moving on to the next, or you'll be still chasing the fault months later and disappearing up you own arse at the same time...

Hope that helps folks...

Miti
(Electronics/Radar/Weapons System Tech Eng and old fart biker for decades now)

[Christian Raith]

Jonesy print this out
The Green (Groen) wire to the rotor winding is what keeps the voltage at 13 < > from the regulator, it supplies the active field for the alternator
If this is faulty then the voltage can go as high as the load will permit
I think it has about >9V, can't remember and the pills are cutting in I will check on mine unless someone knows off hand.

This a cct showing the diodes and regulator as separate pieces, may help to understand what happens, Talk soon

[excess.11]

That's the problem..it s working too good. The leakage or breakdown of insulation is intermittently inducing higher than normal voltages.....at least that's what we are trying to ascertain.
Read my previous post.

[Jonesy :-)]

Ok will do the stator change, but it (the alternator) seems to be working? punching out plenty of volts, just seemed logical to replace melted wires in the harness....to me anyway

[excess.11]

Jonesy....aside from the reg/rec that showed zero......... the second unit that showed 18v seems consistent with the existing unit and measurement. At this stage I would assume the unit is ok ....now change over the alternator.
Was the reg/rec unit that showed 18v off your spare bike ?
I don t know why your considering going down the road to replace only the wiring to the alternator...........as there has been enough damage to melt it s wiring  loom there certainly is the possibility of damage to the winding insulation. With out having the neccesary meter to test this fully............the next step is to change over the alternator field and stator unit complete. No need to change the rotor at this stage.

[Jonesy :-)]

I'm considering replacing the 4 wires in the harness that come from the 4 pin plug behind the fuse box that got melted. I tested 2 other rec/regs and got zero volts to the battery from one of them, and 18v from another.
I posted a similar question on the pommy site just to expand the horizons of similar experiences.

http://xs1100.com/forum/index.php?topic=11591.0