strange charging problem - rectifier or alternator???

[mattye]

Hi all,

So the battery lost its charge and wouldn't start the bike so measured the voltage when I got it running again and only showed 11volts. However the next day I started the bike and it showed 14.5 which is about normal. But what I have noticed is when the voltage going to the battery drops when the bike is runing the lights go a bit dimmer for a couple of seconds and I can hear a sound that I can only describe like a bearing which get stuck. A kind of high pitch wine which only last for a couple of seconds.

I'm thinking it might be the alternator in some way, which I assume rotates in the stator coil, but not sure exactly how the alternator works.

Could it also be the rectifier in some way.

Any thoughts greatly received before i start spending loads a dosh.

By the way changed the battery anyway but didn't make any difference.

thanks all

[viper]

normally id say a bad cell in the battery but as your are describing a noise im thinking altenator bearing . You need to rule out the battery issue first as altenator faults are rare. can you run the bike without the battery to determine Alty fault ?

[mattye]

Viper,

As a precaution I have already changed the battery to rule it out.

If its alternator bearing that seems to account for the noise. would this mean that the alternator stops rotating for a split second and so doesn't send a charge to the battery???

[Andy]

Why did the battery initially go flat? Is the dimming lights / drop in voltage (normal under load) caused by a sticking starter motor (the noise?) ??

[shaggs147]

Hi Mat,
I had a similar problem with a VFR which only started to lose charge after the rectifier got hot. From what I remember, I measured the AC voltage going into the rectifier and also the DC voltage coming out of it. The AC voltage stayed fairly constant, but the DC voltage dropped like a stone as soon as everything warmed up. Maybe you could try the same by getting yourself a cheap digital meter from Maplins? I never had the noise you describe though.

[mattye]

Andy,

Not sure as to the exact cause of the battery going flat in the first place. I use my bike every day and it only stood for 3 days and then the ride to work (45 minutes) and then it wouldn't start. Bike is 2010 so not that old.

Just looked at the price of a new alternator. £445. shit!!

[viper]

Viper,

As a precaution I have already changed the battery to rule it out.

If its alternator bearing that seems to account for the noise. would this mean that the alternator stops rotating for a split second and so doesn't send a charge to the battery???

not sure as I have no experience with bike altenators, but a noise is something mechanical which could be altenator, rectifiers don't make noises . I cant imagine the altenator would stop spinning. What drives the alty on these bikes?

[Barry7]

Going back to my time as a car mechanic, car alternators used to have a diod pack, and if one of the diodes failed it would make the alternator very noisy because one of the AC peaks was not being smoothed out.

So I all I can offer is that this is part of the rectifier and it has failed. I wouldn't run the bike if this is the case as AC voltage and electronics do not get on.

Plus do not disconect the battery with the engine running as this can cause very high voltage spikes that can also destroy sensitive electronics!

Sent from my GT-P3110 using Tapatalk

[doebag]

The alternator is driven directly from the nose of the crankshaft on the l/h side of the engine.

A full test system is in the workshop manual [section 16-36 to 38], but basically, the alternator should be giving approximately 50 volts at medium engine revs, the reg/rec pack should be giving out  about 14.5 volts at the same engine speed.

When the battery went flat, how did you start it, newly charged battery or jump start ?

[mattye]

Doebag,
When the battery went flat I had to get a couple of work mates to give me a jump start.
On the wat home the reading from the bikes display showed the battery at 14.5 volts so it seemed to be getting a charge.

When I started it the next day after fitting a new battery it started ok but was making the noise I have described previously.

Seeing as I have changed the battery the next thing, cheapest thing, to change is the rectifier at £122.

Hopefully this will solve the problem. I will keep you all posted at the end of the week as to the outcome.

Cheers

[shaggs147]

Matte, before you spend 122 quid get yourself a £5 meter from maplins and do the test I described, looking for the voltages Doebag describes. worth a try

[pistole]

if you're getting 14.5 volts at the battery's posts with the engine running , there's nothing wrong with the charging/generating system.

then that narrows to a battery problem.

.

[Martin#30]

My reg/rec recently failed on my 2010, at 49k miles. Chatting with my Kawasaki dealer yesterday whilst mine was in for a service, he also mentioned another similar miles 2010 bike that the reg went on.

I had no symptoms until both headlights failed, which turned out to be a blown relay under the seat, which led me to investigate and find the failing reg/rec. My bike was undercharging, only showing 12.9-13.1V when running.

The second bike had all sorts of ABS warning lights and messages, and his bike was over charging - above 15V.

The workshop manual describes how to test the alternator and the reg/rec in some detail. It is quite an easy process, takes 30 minutes if you have a digital meter capable of measuring both DV voltage up to 20V, and an AC voltage in the hundreds of volts.

The reg/rec is mounted just in front of the rear wheel, down near the rear shock. It is the same part as fitted to all years of GTR and ZZR1400, so plenty of second hand ones out there. I bought one from a 2011 ZZR1400 for £60.

Long winded way of saying do test your bike's charging system per the workshop manual, as a failing reg/rec tends to take out other more expensive electrical components in it's death throws.

Martin

[Burchy]

For information

This page shows that it is used on a whole load of makes/model

http://www.ebay.co.uk/itm/VOLTAGE-RECTIFIER-ORIGINAL-SUN-1-EQUIPMENT-KAWASAKI-GTR-COUNCOURSE-1400-2009-/221396734473?pt=UK_Motorcycle_Parts_13&hash=item338c461209

[shaggs147]

That's handy to know Burchy, nice one. should be loads of second hand stock around. Matte, check your voltages and let everything get hot in case it's breaking down after everything is up to temperature. If it still holds at 14.5 volts after that then maybe you have a drain on the battery somewhere?