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1Back to top Go down   Is this my alternator?? Empty Is this my alternator?? Sun Nov 06, 2011 9:32 am

Cris_A

Cris_A
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Hi guys almost sure my alternator is bad , this is what happen the bike did not want to start checked voltage and is reading 9.2v , hooked my cables and jump started fine , it was running for a good half hour ,after that I turn it off and it wont start again , jump started again disconnected the ( - )to the battery and the engine died , checked for voltage and the battery did not a bit still reading 9V ,so do you agree is the alternator?? thanks for the input


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[b]Cris cheers

87' K100rs 0043923
    

2Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 10:29 am

Inge K.

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Probably your battery that is gone. When jump starting, measure the voltage with the cables connected before starting, and while the bike is running.

See if it is any difference, if voltage goes up when bike is running, your alternator is OK.

Inge

    

3Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 10:35 am

Cris_A

Cris_A
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Inge K. wrote:Probably your battery that is gone. When jump starting, measure the voltage with the cables connected before starting, and while the bike is running.

See if it is any difference, if voltage goes up when bike is running, your alternator is OK.

Inge

I will check the voltage while the bike is running ,but I was told by the PO that the battery had 0 miles he replace it but never rode the bike after that. Thanks for replying


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[b]Cris cheers

87' K100rs 0043923
    

4Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 10:45 am

Inge K.

Inge K.
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If the battery have been standing for a long time and not being in use it would self discharge.
And if it`s deeply discharged for longer time, it usually difficult to bring back to life.

Inge K.

    

5Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 11:28 am

charlie99

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cris ...

does the charge indicator in the instruments ever light up ?

there are 2 wires going to the altenator connection .....the field/regulator wire is the small one at the back (blue wire from memory) take the conection apart and just check that the spade type terminals are free of oxidisation ....a clean up maybe required .

.....there is also a charge indicator in the instument cluster ...if the globe was gone ...kaput ....or the connections at the instuments were dodgy-faulty it also may not charge .

but definatly sounds like the battery has been in a poor state for a long time...lots of folks take the easy way out and cant diagnose or chase down issues and just get rid of the bike ...which is sad ....

heres something that you may like to try .....with a jump start ....after wards ..get a multi meter on it and measure between the field wires and earth -chassis ......it should have some voltage on it ....obviously with the jump from another battery it will still be high (12 volts ) but it would be interesting if it wasnt huh ? which could lead you back to the wiring to and from the instrument panel ...

check the wiring diagrams on the downloads section for the details i guess
as inge has said the voltage should go up ...around 13.8- 14 volts would be a good measurement comming out of the altenator ....but the problem still exists if the battery just sinks the volts and wont raise above 9volts or so that you have measured
but obviously, it must as you areable to jump start the bike .

totally flat batteries take at least 8 hours charging to come up to being good ...whether you put a charger on not ...keep that in mind

of corse the other thought is that there is some thing always drawing power ....even when the power /ignition switch is turned off ...





hope this helps

    

6Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 4:14 pm

Stan

Stan
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After having the pleasure of owning a K for many years, I have found that the one constant I don't like is replacing batteries every couple of years. As soon as it goes down a little you know it won't be long before it has to be replaced. I have seen owners turn the key one stop too far and the parking light goes on. This will discharge the battery and you probably not notice it.


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1983 K100 basic vin 0003960 colour red  GONE
1987 K100RT vin 0094685 colour, orange peel, sorry, pearl..GONE
F800R black
    

7Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 7:35 pm

Rick G

Rick G
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How long was the bike sitting with the new battery in it and not being used. If 18 months or more then there is a 90% chance the battery is kaput and 100% chance it will not ever be a good battery again.
It sounds to me that it is the battery at fault. The charging volts should be 13.8 - 14 volts when the engine is running over 2000rpm.
Put it on a charger for a full day and if it still does not start the bike or is slugish then replace it with a gel battery as they last quite a bit longer and cost a bit more so are good value.
To test the charging light, earth the small blue wire that goes to the alternator and the light should light up when the key is on. The current used to light that light is what starts the alternator charging and if it is blown then there will be no charging.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

8Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 11:07 pm

Cris_A

Cris_A
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First thanks to everyone that responded, second I havent had a chance to check the bike again , but this is my question when I disconnect the negative from the battery while its running and the engine shuts down thats not a sign that the alternator is NOT working ??? my understanding is that the battery job is just to start the bike. I have remove batteries from running cars with good alternator and the engine just keeps running .


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[b]Cris cheers

87' K100rs 0043923
    

9Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 06, 2011 11:27 pm

charlie99

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in modern electronic regulators (altenators ) the most imortant part is the ground connection ....the ground gives a reference for the regulator to regulate to the specified voltage.... i wouldnt be disconnecting the earth at all.... it wouldnt be hard at all to create unwanted voltages that exceed the rating of their internal diode packs of about 50 volts ....above that voltage and they will punch through ...resulting in possible discharge of the battery at a minimum and weak if any charge at all being applied to the rest of the system , other problems may also arise as efi, ignition controls etc may die ...from the over voltage .....think of the battery a voltage sink ...ie a storage device that smoothes out any rises and falls of voltage along the system .



when an altenator is under heavy load .....say powering head lights ...and you turn them off ....there is a huge voltage spike as the regulator compensates for the change in load ( the battery sinks this spike)



in fact it isnt hard to make a real good welder from an altenator ...there are kits available that change the diode pack and the voltage regulators and im told do a fantastic job in remote location applications



food for thought


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

10Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Fri Nov 11, 2011 2:40 pm

K-BIKE

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To reinforce what Charlie said, never disconnect the battery when an alternator is running you may get away with it on idle but at higher revs you can fry not only the alternator diode packs but a lot of the other electronics on the bike or car since they can also see the spike.
Regards,
K-BIKE

    

11Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sat Nov 12, 2011 7:26 pm

Cris_A

Cris_A
active member
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Ok so today I just tested it again , after a week of not running the bike the battery had 10v it won't start so I jump it , and ran fine at 13.5v while running after half hour I turn the bike off and it won't start again checked voltage and battery is 9.6v as I press the start button it drops to 4.8v. While the bike is running all my light are OK in the cluster battery light stays on at the very beginning for a few seconds and it goes away bike idles fine . So it seems that the alternator is doing its job by raising the voltage while running but the battery doesnt hold voltage .....so bad battery ???? who agrees?? Thanks for all the help !


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[b]Cris cheers

87' K100rs 0043923
    

12Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sat Nov 12, 2011 7:50 pm

Rick G

Rick G
admin
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Yep it's the battery alright couldn't get a more classic case than that.
My advice is to get a gel (AGM) one as they last a lot longer and don't leak.
They cost more but are certainly worth it.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

13Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sat Nov 12, 2011 9:18 pm

K-BIKE

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When you say running for half an hour do you mean idling or you went riding for half an hour because idling is flattening the battery there is not enough output from the alternator at idle to charge the battery. At idle the battery is discharging when the engine is over 2000 rpm the battery is charging.
Regards,
K-BIKE

    

14Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 13, 2011 1:24 am

charlie99

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verry good point k-bike .....

but here is the clue .......if the battery was discharged and able to take a charge ,,,,the voltage on the battery as soon as the bike goes to charge mode would be somewhere lower than 14 volts (more like 12.5) as the battery would suck the living daylights of all the energy that the alternator could give ,,,,till at least it was able to recover to a high percentage of charged condition...at which time the charge demand would be way less and then the voltage rise towards the magic 14 volts ....change the battery ....then do the measurement with a good one and you will see what i mean ......


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

15Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 13, 2011 1:41 am

Cris_A

Cris_A
active member
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K-BIKE wrote:When you say running for half an hour do you mean idling or you went riding for half an hour because idling is flattening the battery there is not enough output from the alternator at idle to charge the battery. At idle the battery is discharging when the engine is over 2000 rpm the battery is charging.
Regards,
K-BIKE

Aaaahhh!!! this is good to know , I always tried to charge the battery at idle only , maybe that's why it wont charge , like I mention in previous post the battery according to the PO is brand new I will say new from this past May , and he never rode the bike and I only put about 350 miles since I got it 2 months ago , it will suck to change it is a new gel battery adventure power I think is the name , maybe I should go for a ride to see if it charges before throwing away a good battery .....how long of a ride will it has to be for the battery to charge ??? Thanks great intel !!


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[b]Cris cheers

87' K100rs 0043923
    

16Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 13, 2011 1:57 am

K-BIKE

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Bottom line to determine how long it takes to recharge a good battery that is just flat you need to do a rough calculation of what current you have available for charging.

Yes the alternator can deliver 32 amps but that is at maximum output and taken off that are any lights you run, the fuel pump, the ignition, the injectors, and the various electronic modules. With speed up and slow downs on the average road you will probably have only an average of say 10 amps available remaining to charge the battery.

The best solution would be to put it on a Ctek 3600 battery charger on de-sulphation mode at least overnight and then leave it on that for a few days and see what happens, you may be able to at least partially recover it. http://www.ctekchargers.co.uk/ctek-xs3600.php

Don't attempt to start the bike with a flat battery you risk welding the starter relay contacts and then you can't stop it cranking without disconnecting the battery lead.
Regards,
K-BIKE

    

17Back to top Go down   Is this my alternator?? Empty Re: Is this my alternator?? Sun Nov 13, 2011 2:18 am

charlie99

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again great advice k-bike

    

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