Charging System checking

How can i check if the charging system is working on my SV650s 99 model?

[johnnyrod]

Take a look in the manual's electrics section, I think you can download it as a huge PDF but not sure where from. Otherwise I send people here and they seem to get on okay:

http://www.bikeguru.fsnet.co.uk/alternator.html

Rev the engine with the lights on. They should brighten when you do this. Not sure if this is a foolproof way of checking though.

[Sid Squid]

First charge the battery and check the voltage across the battery terminals, (not immediately after disconnecting the charger, you'll get a falsely high reading), should be about 13V, much less and the battery is past it's best, do this first as some supposed charging system faults are duff batteries.

With the lights on and the engine spinning at 5000rpm there should be a reading of between 13.5 and 15V at the battery, if the reading is above 15V the regulator doesn't, if it's below 13.5V either the regulator is toasted or the alternator or wiring is goosed. This is a good rule of thumb test, but does assume that your meter is reasonably accurate, if you're not convinced your meter is accurate try this:
Ensure the battery is fully charged, start the engine, turn on the lights and rev the motor to about 5000rpm, what you're looking for is a rise in the reading of at least a volt, and when the engine speed falls back to tickover that it's still either equal to or preferably a bit above whatever reading you got from the battery alone.

What he said!

Sid, did what you said and got the following
ignition off battery voltage 12.9
bike running at tickover lights off voltage 13.2
bike running at 5000 rpm lights off voltage 13.2-13.4
bike running at tickover lights on voltage 11.9
bike running at 5000 rpm lights on voltage 12.4

hellllllp

[Sid Squid]

OK, that don't sound too good, the obvious prob being the 11.9 reading at tickover, are you sure that the battery is OK? This can affect the results so be sure about this.
Assuming you are confident of the battery, it sounds most likely that the regulator rectifier is isn't doing so well, but first a check of the alternator output will determine this, do this: disconnect the reg/rec unit connectors and identify the three yellow wires, these are the alternator connections, and they can be considered to be three pairs, that is if you were to name them A, B and C, you could have a pair A and B, a pair B and C, and a pair A and C. using a voltmeter with an AC setting of about 100V check the output between each of the three pairs, at about 5000 rpm there should be about 70V AC, the most important thing is to satisfy yourself that all three pairs are about the same output, any one markedly different reading will stand out.
If the alternator passes this test, (there are other tests too, but I doubt you'll find anything amiss with it anyway), then you may be confident that the trouble lies in the reg/rec unit, remember, this includes it's connections, so check that all is well fitted, clean and not suffering from corrosion.
If you find you need to replace the reg/rec unit - I suspect you will - consider a better one from a Kawasaki or a H***a, these will require a small change to the wiring, if you want to do that ask me for details.

Sid,

I guess that there may be some others who are watching this with their fingers crossed. Do you have a list of some 'more robust' units from other manufacturers that can be used?

Paul

[Sid Squid]

Not a list as such, no. What's needed is a reg/rec unit from a bike with a similar alternator output/level of electrical equipment, in practice this means pretty much anything 500 and up from the last ten years or so, (and plenty others bigger and smaller besides), if you go to a breakers and find any old junker CBR6 or similar you'll have something ideal in your hand.
The major difference you'll notice is that your new 'leccy bit will have six connections instead of the five the original has.

Thanks Sid,

I'm hoping that it's just my battery thats gone south for the winter (it's 4 years old !). As soon as the new one is fully charged I'll re-check the reg charging - here's hoping