So that might be why the charge light kept coming on!

mr_magicfingers

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A couple of weeks ago, riding home in the rain, the charge light started coming on, as did my battery monitor. It stopped after a while and all was well, but today I pulled the tank off to take some measurements and check the connections.

What I found was the little spade connector with the two blue wires was dodgy. I went to pull the connector off and the wires came away from it. Hmmm. might be a reason here.

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I trimmed and stripped the ends then crimped a new connector and soldered for good measure, polished the spade tab with emery paper, fitted the connector, applied a good dollop of silicon grease and then the rubber boot, so that should be good for a while.

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Then I took the big alternator wire off, which was in good condition, cleaned the connector, refitted it and covered with silicon grease, just for good measure.

Now, looking at the circuit diagram, the blue wires only go to the diagnostic plug and the charge light on the dash. So, if the connection was broken would the light come on or stay off. Basically, would the broken blue wires mean it's just showing a bad charge when it's actually ok, or have I found a problem separate from the original one.

Given that the separate battery monitor I have fitted gave the same warnings, I'm thinking that the battery wasn't getting charged, so was the blue wire fault the cause of this or do I need to be looking for something else.

Testing before I did anything but with the bike warmed up showed the battery at 12.9v with the bike off and 13.8 at idle.

Testing once it was all back together again gave the following readings.

idle with no lights on: 13.8v
dip beam on: at idle 13.5v, at 4000rpm 13.6v
dip beam + 2x35w fogs: at idle 12.6v, at 4000rpm 13.3v
dip beam + 2x35w fogs + main beam + 2x35w spots: at idle 11.7v, at 4000rpm 13.1v

Be grateful for your thoughts.
 
The readings you are getting look reasonable, there will be some variation as you probably do not have calibrated meter. If the blue wire breaks or becomes detached the alternator/charging lamp will not come on, however the warning bulb does have a power feed to the other side of it so if the blue wires touched an earth it will come on. Hopefully this is what was happening so your problems should be solved.
 
right..

factor in some more bits.
70w +70w +55w(20a)+fuel pump(5a)+dash lamps+rear lamps etc,etc ecu etc total load probably about 30a.
I would suspect you may have a phase down on the alternator.
I believe, and (i'm trying to get out the door) that it is a 60a alternator.
I would guess you have a unit pumping out 2/3 output ie 40a, hence low charge getting to battery.
Youre next step it to borrow an oscilloscope, this should show 3 peaks, as in the 3 phases,i bet you only have 2.
The other thing you could do is temp extend the alternator large terminal wiring , so as to be able to a current clamp on the output side of the alternator, which would show up the current being sent from the alternator.
On a normal bike this would be fine,(low load) and you would never now there was a problem,however as your bike is like blackpool, the fault has shown up.
Ive a dc current clamp you can borrow if you need one.
atb Paul
 
From memory the blue wire is an earth, when the alternator kicks in the wire has no earth and your charge light goes off. So would not worry about it, looks like you found the problem.:beer:

So what warmshed said ^
 
How come you have 2 blue wires on that connector? Do you run the ABS relay mod from there too? All what I have seen only have 1 wire in there... Yes, blue.

Dan.
 
There are two blue wires, one to the diagnostic plug, one to the warning light. It gives out alternator voltage (via a diode pack) this is fed to the lamp which has battery voltage on the other side. When the alternator voltage rises, the voltage either side of the warning lamp becomes closer. Once the alternator output is up to battery voltage the lamp goes out as there is now no potential difference across the bulb.
I still think the alternator output at 4000 revs with, ignition, main , spots and fogs and still reaching 13.1V is fine. The regulators vary and can cut off at 13.8 max, the voltage you get at idle with no lights on. Remember the battery is also being charged, maybe accounting for your suggested "lost" output.
 
I get 13.8V from just above idle until close to 7k rpm with the main beam on, fogs, hazard lights on and brake on. 13.1V is something I would be worried about. But that value works just fine for jap bikes with their rectifiers :D

Dan.
 
I had a similar problem few months back the battery monitor light would act like a set of traffic lights cycling through red, amber green and and a variation of those:blast

so took alternator off all seemed fine , decided to replace voltage regulator and vola all is well in the alternator now.


found a replacement on the net not from bike supplier but an auto electrical store for half the price :thumb2
 
Make sure your battery is fully charged before taking the output readings. This will bring down the voltage. Try to compare your meter with another known one so you don't go looking for a fault that is just a meter reading a bit low.
 
and dont forget that voltage is just a reading .. amps is the key..

an alternator works in a simple but clever way, when the ign is switched on the small wire terminal acts as an earth throught the internals and when the unit it rotating triggers the alternator to start charging now when this happns the alternator sends voltage up the wire dropping the earth and putting the light out.. shimplesch.
 
Is that blue wire(s) the exciter connection on the alternator?
 
Nearly..

The alternator exciter circuit passes battery voltage through the alternator bulb and the rotor to ground. No alternator light means no current to excite the alternator.

http://www.horizonsunlimited.com/tech/R-charging-maintenance

That's if it all applies to an 1150:thumb

If you want to test it, unplug the blue wire and ground it, the alternator warning lamp should illuminate.The earthing out of the blue wire may have been the flashing you had.
When the alternator generates electricity, the small terminal is fed with a positive from inside the alternator, this in turns extinguishes the bulb, two postives wont light a bulb.The rotor is now excited. woohoo..
What the bulb does is send power into the alternator through the blue wire,, its called an exciter wire.
If the bulb fails the alternator wont charge until you hit about 4k rpm then it will self excite.dont know why, but it works.
The alternator unlike a dynamo has no conventional magnet, a dynamo has a fixed magnet,and an alternator has a variable electromagnet.
The blue wire starts a small magnetic field up inside the rotor(the bit that revolves), the small current is sent in via the brushes and slip rings.
When the rotor rotates,now with an electromagnetic force inside it , this reacts with the static windings and generates electricity, and the voltage is monitored by the regulator, now the clever bit, the regulator varies the current sent to the rotating magnet(rotor), the stronger the magnet the more electricity is made, the weaker the magnet, the less is made.
When the brushes wear out, the rotor doesnt make magnetism because its power source cant get in, so no power is produced.also if the regulator fails it doesnt energise the rotor either.
If your alternator fails,9/10 it will be the brushes or reg.
the static windings hardly ever fail.never say never.
With a dynamo its different, the magnetism is fixed because the magnets are unadjustable, and the current is made in the rotor, and you have to get the current from the rotor out, this is conveyed thru heavy duty brushes,the downside is brushes cant really convey more than about 30-40 amp.
Hence with motor vehicle progression, the need for extra power for all those extra gadgets involved the need for the development of the alternator.
Also because a dynamos output is relatively rpm fixed, you had to be tramping along to get a decent output,but with the alternator it makes more current lower down the rev range , because the reg can up the power in the rotor and make a lot of energy with slower rpm's by using a feck off powerful electromagnet.
I'm warbling a bit here.
When you get a phase go down(alternators are 3 phase) like having 3 generators in one unit,using a common magnet, you get the magnetism only working in two of the outputs, so only making 2/3 power.
When the energy is produced it has to go through a one way valve(diode) which stops the electrons racing back and forth due the north/south poles changing as the rotor goes round, every phase has a diode, grouped they are called diode pack.
This also serves another purpose, to stop the battery sending electrons back into the windings,when the engine is stationery, when a diode fails, electrons come from the battery and go right back into the windings and meet earth, and make the alternator nice and warm even though the engine isnt running,thus flattening the battery.
does that help?This really applies to the car type alternator fitted to the gs.
Jap motorcycle alternators have an external regulator, the 3 phase windings are immersed in oil inside the engine,and the magnet in the rotor is fixed, and not electromagnetic.Thus constant current is generated and this is controlled by an external regulator which uses transistors to the vary the output to the battery as controlled by the voltage control circuit within the regulator itself.
Thats why the jap style regulator has a finned heatsink, this is because the transistors within the regulator switch high currents on and off and get hot as a by product.
 
Nice run through Nomad, however most dynamos used on cars and bikes do not have fixed magnets, they have electromagnets like the alternator except they are fixed to the outside and the current generated in the spinning armature. This enables the voltage to be collected at the right time by the commutator and brushes for each coil so that the output is DC (well varying DC that the battery can smooth out). The field coil electromagnets can self excite as the retain enough magnetism to get the output started which is fed back to the field coils to make the electromagnet stronger to make more output.... The regulator controls the power being fed back to the field coils to keep the output regulated, there is normally a current sensing circuit to limit the current even if the voltage is within limits. Typically the regulator is remote from the dynamo (but not always).

The early alternators are the ones that had fixed magnets as a rotor with coils around the outside called a stator. They were fitted to the later airhead boxers, Guzzis and most late British classic bikes and many Jap bikes.. Regulation was crude initially just dumping excess via a zenner diode, later ones used more sophisticated solid state regulation.
 
talking of technology

did you have any luck with the nifty lamp you offered at the last camp?
cheers Paul
 
factor in some more bits.
70w +70w +55w(20a)+fuel pump(5a)+dash lamps+rear lamps etc,etc ecu etc total load probably about 30a.
I would suspect you may have a phase down on the alternator.
I believe, and (i'm trying to get out the door) that it is a 60a alternator.
I would guess you have a unit pumping out 2/3 output ie 40a, hence low charge getting to battery.
Youre next step it to borrow an oscilloscope, this should show 3 peaks, as in the 3 phases,i bet you only have 2.
The other thing you could do is temp extend the alternator large terminal wiring , so as to be able to a current clamp on the output side of the alternator, which would show up the current being sent from the alternator.
On a normal bike this would be fine,(low load) and you would never now there was a problem,however as your bike is like blackpool, the fault has shown up.
Ive a dc current clamp you can borrow if you need one.
atb Paul

Hmm, sounds plausible. I don't know anyone with a scope, though I saw one of these recently http://www.hobbytronics.co.uk/dso-nano-oscilloscope and the geek in me just wanted one :)

I'll have to ask around and see if I can locate someone with a scope.
 
So where can you use a scope to check the phases, i.e the connection point?? Also, if you can get a scope in there with the engine running, why not just use a meter (AC setting) and go phase to phase?
I bet its the diode pack, although Im not sure if these can be obtained on their own?
As Nomad said, a breakdown here could result in a lost phase which under normal circumstances would proberbly not be noticable. Indeed IIRC Suzuki used to run the old GS series bikes with just two phases until you switched the lights on which connected the third.
 


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