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Re: Alternator no chargy

To: mgs list <mgs@autox.team.net>
Subject: Re: Alternator no chargy
From: Jon <a77mgb@yahoo.com>
Date: Mon, 13 Nov 2000 08:53:20 -0800 (PST)
I have never seen the ignition warning lamp. I don't
think it has ever worked. The alternator was surely
working until very recently. I got a chance to take a
few measurements this morning, in the cold rain before
work. Being safety minded, I always do my electrical
work in the rain:

Running at about 1200 RPM (after exceeding 3000, I
think), the output measured slightly less then battery
voltage, maybe 11.5 VDC.

With the alternator unplugged I measured about 1.5
Volts DC on the output referenced to ground. I flipped
the meter to AC and measured 5 to 8 VAC, fluctuating
somewhat. 

BTW: by *output*, I mean the terminal where the BIG
wire goes.

Also the battery went completely flat over the
weekend. It was charged to 12 volts. This morning it
was so dead the clock stopped (honest, it wasn't my
face that stopped the clock). I did above measurements
after charging the battery.

So, does the 1.5 VDC mean a bad regulator? Or does the
fact that is discharges when sitting for a few days
mean a shorted diode? 

Anybody know about what the stock late 70's ('77)
alternator is rated at in terms of Amps?

Printed Larry Hoy's Delco article out. Seems to be the
most cost effective rout, but since time is also a
concern, I might go for a diode or regulator.

jon
--- paul.hunt1@virgin.net wrote:
> Speaking of ignition warning lamps, what is yours
> doing?  It is possible for
> a failed lamp to affect charging in that the engine
> may need to be revved to
> 3k or so to get it to start, once started it will
> charge normally down to
> and including idle speeds.  It is possible that a
> brand-new alt in
> conjunction with a failed warning lamp may not start
> charging at all.
> 
> PaulH.
> 
> 
> ----- Original Message -----
> From: Jon <a77mgb@yahoo.com>
> To: mgs list <mgs@autox.team.net>
> Sent: Friday, November 10, 2000 2:51 PM
> Subject: Alternator no chargy
> 
> 
> > Hey gang,
> >
> > My alternator seems to have died. Battery measures
> a
> > lower voltage running than off. After charging it,
> it
> > slowly drops until dead.
> >
> > Isn't there something with the ignition lamp or
> other
> > warning lamp that can make a good alternator
> appear
> > bad?
> >
> > How many amps is she rated at?
> >
> > Any reason to keep the original alternator in leu
> of a
> > Delco conversion other than originality? My
> thinking:
> > regulator and or diodes alone cost as much as a
> Delco
> > would cost a mere mortal, but being a jeeper, I
> happen
> > to have two spare Delco's on the shelf, so that's
> > *free* to me. I'm sure I have a bracket that will
> > work. Also I assume the Delco is at least as good
> of
> > alternator. No?
> >
> > Hey if worst, comes to worst, maybe I should drop
> in
> > my spare Buick 231 ;-]
> >
> > Cheerio,
> > jon
> >
> > =====
> > 77 MGB "Christine" slowly, with black cow catchers
> >
> > 58 Willys CJ-3B, the Killer-B
> >
> > C'mon Al, quit grovelling, if they're too stupid
> to punch a hole in a
> card, they probably shouldn't be deciding who should
> be the leader.
> >
> > __________________________________________________
> > http://shopping.yahoo.com/
> 


=====
77 MGB "Christine" slowly, with black cow catchers

58 Willys CJ-3B, the Killer-B

C'mon Al, quit grovelling, if they're too stupid to punch a hole in a card, 
they probably shouldn't be deciding who should be the leader.

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