Voltage reg?

[Cody Forbes]

I cant dissagree with any of that. I am still finding it odd though  
that all of the sudden it's charging much better than it ever has. For  
various reasons I have watched voltage (sometimes out of boredom I  
turn on the volt meter on long trips) and have never seen more than  
13.5v.

This is my backup car and by the end of next week will be on reserve  
status again as my 'fast' 5ktq will be running with it's new  
configuration. I'll go through all of the grounds then and check some  
things out. I may put a volt meter right on the battery Monday too  
just to get some double checking done.

-Cody (mobile)

On May 15, 2010, at 10:19 PM, Huw Powell <audi at humanspeakers.com> wrote:

> I suspect your car is behaving "normally".  The tach fluctuation  
> made you start watching the voltmeter.  I suspect that part of the  
> issue may be that the voltmeter is down a long chain of junk and  
> sees a "pulled down" voltage that does not necessarily reflect the  
> actual charge state.
>
> I recommend hook up a separate VOM to, say, your battery posts and  
> observing what happens directly there.
>
> No harm in pulling the reg to check the brushes as well, of course.
>
> Cody Forbes wrote:
>> And one more update for today. I'm still seeing high 13's on  
>> average,  but then I turned on the vent fan. With the fan on it  
>> went from 13.8  to 12.3v immediately. Lights and fan took it to  
>> 11.0. When I turned  the lights off but fan still on it read 11.4.  
>> Upon stopping and  turning the fan off it shot immediately up to  
>> 14.3.
>> So maybe the VR is marginal, but it seems like the fan may be on  
>> it's  last legs too. Odd that it doesn't squeek or anything.
>> -Cody (mobile)
>> On May 15, 2010, at 6:08 PM, Cody Forbes <cody at 5000tq.com> wrote:
>>> Update:
>>> On the way home it got more interesting. With no loads it now   
>>> charges at 13.8-14v steady at idle, and fluctuates 13.4-13.8v  
>>> above  idle. As we got closer to home I turned on a bunch of  
>>> loads  including lights. It dropped to 12.5v initially, but after  
>>> a few  seconds crept back to 13.3v. It still is fluctuating more  
>>> that I  like, but overall the thing just seems to be better than  
>>> it has in  many years. It's beyond me why it charges more at idle  
>>> than it does  above idle. I'll keep it under supervision and post  
>>> if anything  changes.
>>>
>>> I got a note or two about that it should always charge 13.5 or   
>>> better. Yes, this is true for nearly every car out there, but it   
>>> just doesn't work out like that on a 5000. Most 5000's charge at  
>>> a  very peak of 13.5 under ideal conditions  with voltages under  
>>> heavy  load being less. The only real fix is Avi Merons Ultranator  
>>> or at  least the VR he uses.
>>>
>>> -Cody (mobile)
>>>
>>> On May 15, 2010, at 5:35 PM, Cody Forbes <cody at 5000tq.com> wrote:
>>>
>>>> I haven't seen a failure mode quite like this before so I shal  
>>>> employ
>>>> the collective wisdom. Seems like a voltage regulator failing, but
>>>> could maybe be bigger.
>>>>
>>>> So I'm cruising down the road in my '87 5ktq taking the family to  
>>>> the
>>>> mall. At one point I noticed the tach fluctuate a little. Not quite
>>>> like the old bouncing tach syndrome, just a lazy ~300rpm  
>>>> occillation
>>>> while the engine was definately steady. I pulled up the volt  
>>>> meter in
>>>> the climate control head and noticed that we were down to 10.3v. I
>>>> immediately turned off the A/C and the voltage came quickly up to
>>>> about 12.5v. This car has never been a great charger for the 4  
>>>> years
>>>> I've known it and two that Ive owned it, usually 12.8-13.0  
>>>> daytime  and
>>>> low 12's at night with lights and everything going. Anyways, when I
>>>> stopped at the next light the voltage very quickly rose to 14.0v  
>>>> with
>>>> the engine at idle. As soon as I raised the revs to pull away it
>>>> dropped back to 12.5v. We were more than halfway to our  
>>>> destination  so
>>>> I decided to motor on. On the highway voltage fluctuated 12.3-12.9.
>>>> Back off the highway I noticed the voltage fluctuating with the
>>>> cooling fan as it should, but it was swinging from about 12.3  
>>>> with  the
>>>> fan on to near 13.8 when it turned off.
>>>>
>>>> -Cody (mobile)
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>
> -- 
> Huw Powell
>
> http://www.humanspeakers.com/audi
>
> http://www.humanthoughts.org/