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Re: Alternator Woes

To: "roadster List" <Datsun-roadsters@autox.team.net>
Subject: Re: Alternator Woes
From: Eric Frisbee <efris@home.com>
Date: Fri, 09 Jun 2000 13:18:35 -0600
Quite right you were... the PO had an inline fuse buried under yards of
electrical tape... fuse was blown... now it's out and happy... now for
the strange stuff...  confirmed that the battery is indeed hooked up and
getting 12V at the alternator connects with the car off.. great!  Start
the car and see... 12V... rev up and stays at 12V.   Hummmm???   Unhook
primary wire, and seeing 2.5-4V from the alternator??  Why doesn't it
charge with the battery on?
I also confirmed the ammeter is working great too ( that was part of the
initial problem, so replaced it with one I had tested on this very car 2
days before the car died)

Uh oh... guess I'd better toss out that Sears "Made in China" meter I
have... :)  My brother bought a Fluke for his electrical woes on his '68
1600... WOW!  I know what I'm going to ask for Christmas now!   
Question though.. would that cheapo cause readings to be THAT far off??  

Eric
WyCROC

Thomas Walter wrote:
> 
> Eric,
> 
> On the "SINGLE WIRE" self exciting alternator... you need
> to connections. A good ground, and the other connection
> to a BATTERY.
> 
> Since you only measured "3V" on the positive post, you are
> not hooked up to the battery at all. Should be around 12.5,
> once charging you should see around 14.0 Volts.
> 
> I do recommend running the alternator connections DIRECT
> to the battery for checking everything out.  You might have
> a fried ammeter that is internally opened.
> 
> A nice tool is having a "clamp on" DC CURRENT PROBE for
> a good FLUKE Test Meter. You can at least tell the current
> flowing through the wire.  Of course being cheap that I am,
> I just measure the voltage drop across a known wire, and
> "guesstimate" as to the current flowing through the wire.
> Once again those cheap "taiwan" test meters for $15... toss
> into the nearest trash can. Spend $80-$200 for a decent FLUKE
> test meter, and you'll save hours of frustrations in the long
> run.
> 
> Cheers,
> 
> Tom Walter
> Austin, TX
> TDROC
> 
> Eric Frisbee wrote:
> >
> > Lots of great advice so far! thanks!  Here's what I have so far...
> > It's an AC Delco... It looks brand new, in fact, found a receipt for
> > it... less than 12 months old by the receipt, so it is brand new, but I
> > tested it anyway... 14V under load and works perfectly.    I have it
> > mounted in a early '67 on the right side.   I have a ground wire run to
> > the grounding post on the alternator.  The old primary wire for the
> > original alternator is run to the positive post on the new alternator.
> > With all this connected and working, I fired up the car and revved to 2K
> > RPM... moved it up to 2500 and got a solid 3V on the multimeter.  3K-5K
> > didn't produce any different results, it remained at 3V.     Hope this
> > helps anyone thinking on this problem...  I'll continue working on it
> > some more tonight...  Aren't these Delco conversions fun???  :)
> >
> > Eric
> > WyCROC

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