AirSpeed VW Community Forums

Technical => Electronics & Car Audio Forum => Topic started by: Richard Kuczko on August 02, 2013, 11:15:59 AM

Title: 6v generator problem
Post by: Richard Kuczko on August 02, 2013, 11:15:59 AM
My wife's battery keeps dying and I want to check with a volt meter if it still works.  I hooked up the volt meter and it idles at 6. But when I rev up the rpms it drops down in numbers.  It that normal or is the generator done
Title: Re: 6v generator problem
Post by: Richard Kuczko on August 02, 2013, 01:42:44 PM
This video is what it does
http://www.youtube.com/watch?v=IdDX9AnU7gg&feature=youtube_gdata_player
Title: Re: 6v generator problem
Post by: bwaz on August 02, 2013, 01:56:55 PM
no expert, but sounds more like the voltage regulator? Did you meter out of the gen or regulator?
Title: Re: 6v generator problem
Post by: Richard Kuczko on August 02, 2013, 05:43:18 PM
The regulator.  And I put in the second one and it did the same thing.   So how do I check the generator
Title: Re: 6v generator problem
Post by: BUSDADDY on August 02, 2013, 07:29:45 PM
It's described in the Bentley manual, should be ground the field and test the loose D+, but pay attention when they say "don't rev it up and only test a few seconds", should make crazy big volts, have you polarized it?
Title: Re: 6v generator problem
Post by: Richard Kuczko on August 02, 2013, 08:03:04 PM
It should be.   It's the original gen.   And it was working fine before
Title: Re: 6v generator problem
Post by: Richard Kuczko on August 02, 2013, 08:06:27 PM
Yeah when I test it for a few seconds.  It reads 6 or slighty higher...and if I rev it a tiny bit the reading will go as hight as 8. But then start going goofy and the numbers drops as low as 2 to 3 volt.  So I thinking it might be ok.  Any second opinions
Title: Re: 6v generator problem
Post by: BUSDADDY on August 02, 2013, 10:05:41 PM
But then start going goofy and the numbers drops as low as 2 to 3 volt. 
That's not good, I assume you have checked the brushes? If it drops off after a bit there's a good possibility it's been overloaded and the solder has let go in the commutator or some connection in there has just plain died of old age. With the field grounded it should make 6-8 volts all day (don't actually try that) and much higher voltages when revved up (careful, it'll melt the insides if you do it too much).
Title: Re: 6v generator problem
Post by: Richard Kuczko on August 03, 2013, 05:36:59 PM
Thanks...I think ur right that it was over loaded.  I think someone ran a 12v in it for a bit before I got it and restored it...it had a old 12v in the boot and was wondering why it was there...I have another.   But man it sucks to replace.  Pretty much have to remove the engine.  Thanks daddy