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Main Area => General GS500 Discussion => Topic started by: kml.krk on December 13, 2011, 08:50:58 PM

Title: Charging issue, is it alternator?
Post by: kml.krk on December 13, 2011, 08:50:58 PM
Voltage when idling is around 12.6-12.8, revved up to about 1500-2000RPM it is around 13.6 BUT then the more I rev the more it drops and at about 5000RPM voltage is 12.6 which means it is not charging at all.

I just found Kerry's post on what and how to check here: http://gstwins.com/gsboard/index.php?topic=38480.msg431967#msg431967
But since I already failed the first test he mentions what do I need to do? Is it alternator that is faulty? Can I fix it? Where can I buy one? if I get it on eBay it will probably work as good as mine...

I'd greatly appreciate your help

PS. Battery is in PERFECT condition. It is Bikemaster GEL battery that I load tested today. No issues with battery. It holds charge well and it charges well from Black& Decker smart charger.

Thanks in advance for your help
Title: Re: Charging issue, is it alternator?
Post by: adidasguy on December 13, 2011, 09:29:32 PM
FYI: I have measured things while working on a regulator electrical video.
Odd, but voltage does drop as RPM's go up. I figured it was due to extra current used to fire the spark plugs more times per minute than at a slow RPM.

I'd say the regulator since the battery is OK. What is the resistance between stator terminals? What year is your bike? Possible the stator is not connected properly if an older bike with the 3 barrel terminals on the stator. Check and clean terminals from voltage regulator. Apply contact cleaner/lubricant.

Only other thing is some extra stuff on your bike using lots of power or a short in a +12 line somewhere.
Title: Re: Charging issue, is it alternator?
Post by: kml.krk on December 15, 2011, 08:34:02 AM
bike is 2004. I bought it with 800 miles on the clock so I do not think that anybody messed with electrical system. That would solve the issue of wrong connections.

Another thing that is very noticeable is dimming head light when I hit the brakes.

Nothing else is using electrical power on my bike.
Title: Re: Charging issue, is it alternator?
Post by: noiseguy on December 15, 2011, 10:44:33 AM
Quote from: kml.krk on December 13, 2011, 08:50:58 PM
But since I already failed the first test he mentions what do I need to do?

What you need to do is keep reading the article and test the stator next. If it's good then you likely have a dead regulator.
Title: Re: Charging issue, is it alternator?
Post by: Paulcet on December 15, 2011, 11:08:42 AM
Quote from: noiseguy on December 15, 2011, 10:44:33 AM
Quote from: kml.krk on December 13, 2011, 08:50:58 PM
But since I already failed the first test he mentions what do I need to do?

What you need to do is keep reading the article and test the stator next. If it's good then you likely have a dead regulator.

Yeah, what he said.  However, the 2nd regulator on my bike (a $40 new aftermarket part) had the same symptoms: voltage dropped as rpm increased.

The slight increase in current for higher rpm is far less than the increased output from the stator.
Title: Re: Charging issue, is it alternator?
Post by: kml.krk on December 16, 2011, 01:44:50 PM
as soon as I am done with my finals I will investigate that further. For now I just recharge every week or so to keep enough juice in the battery.

thanks for the tips!