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Re: generators and pos ground

To: paul.hunt1@virgin.net
Subject: Re: generators and pos ground
From: James Nazarian Jr <James.Nazarian@Colorado.EDU>
Date: Mon, 31 Jul 2000 13:39:23 -0600 (MDT)
thanks so much Paul.

James Nazarian
'71 B roadster
'71 BGT ever so slowly turning into a V8
'63 Buick 215 

"Aerodynamics are for people who cannot build engines"
Enzo Ferrari

On Mon, 31 Jul 2000 paul.hunt1@virgin.net wrote:

> James - just noticed I typed '.05v' instead of '.5v', so it looks like your
> field winding is faulty, particularly as it measures 0.5 ohms instead of
> 6ohms which is what my manual for an MGB says as well (there will be little
> difference in design and spec for cars of a similar era with similar
> electrical loads, the huge disparity in cost probably reflects rarity).  The
> yoke is the metal former it is wound on, at ground potential, i.e. same as a
> mounting 'ear'.  Quite possibly the insulation has broken down between turns
> of the field winding, in which case it needs professional repair or
> replacement.
> 
> PaulH.
> 
> ----- Original Message -----
> From: James Nazarian Jr <James.Nazarian@Colorado.EDU>
> To: <paul.hunt1@virgin.net>
> Cc: <mgs@autox.team.net>
> Sent: Monday, July 31, 2000 7:35 PM
> Subject: Re: generators and pos ground
> 
> 
> > well, when connecting D,F terminals together we get .57 volts with no
> > change whatsoever when increasing RPM.  The manual said to check field
> > coil between field coil terminal and generator yoke (don't actually know
> > what that is, but assumed it to be mounting ear on generator)  of the
> > 6ohms expected we got .5  Couldn't say anything for the warning light
> > since we have only had the car 1 week and I hadn't seen it on it may not
> > be working.  While I am thinking of it, this is a 1098 motor, not the 948
> > that belongs in this car, your directions seemed like a quote from the
> > shop manual, presumably this all holds true for the 1098 as well as 948
> > but should the resistance in the field coil be any different?  The nice
> > bit is that the generator for 1098 is $65 while the one for the 948 is
> > $200.  Thanks for the help.
> >
> > James Nazarian
> > '71 B roadster
> > '71 BGT ever so slowly turning into a V8
> > '63 Buick 215
> >
> > "Aerodynamics are for people who cannot build engines"
> > Enzo Ferrari
> >
> > On Fri, 28 Jul 2000 paul.hunt1@virgin.net wrote:
> >
> > > Start the car and monitor the voltage on the brown circuit.  You should
> see
> > > better than 12.7v, and hopefully around 14v if the system is charging,
> less
> > > than 12.7 if not.
> > >
> > > If not, disconnect the wiring from the D and F terminals on the
> generator.
> > > Connect the two terminals together, and connect a voltmeter from that
> > > connection to ground.  Start the car BUT DO NOT REV IT.  Slowly increase
> the
> > > revs while watching the voltmeter.  Do not exceed 20v, this should
> happen
> > > before 1000 rpm.  Do not rev the engine to achieve 20v.  If this test is
> OK
> > > the generator itself is good, the problem might be in the control box.
> > >
> > > If you only .05v to 1v the field winding may be faulty.  If you only see
> > > about 4v to 5v the armature winding may be faulty.
> > >
> > > The cut-out relay in the control box should operate when the generator
> is
> > > putting out between 12.7 and 13v, this should connect charging voltage
> from
> > > the D terminal to the B terminal, and incidentally extinguish the
> ignition
> > > warning light.  This light should come on when you first turn on the
> > > ignition and go off when the system is charging.  If the warning light
> does
> > > not work then shame on you, and that's what you get for ignoring it.
> > >
> > > PaulH.
> > >
> > > ----- Original Message -----
> > > From: James Nazarian Jr <James.Nazarian@Colorado.EDU>
> > > To: <mgs@autox.team.net>
> > > Sent: Thursday, July 27, 2000 8:35 PM
> > > Subject: generators and pos ground
> > >
> > >
> > > > How does one go about testing a generator
> > > > and what quantity of juice should it be producing. I know on a B you
> want
> > > > to see about 14.5 volts on a well charging car, but how about on a
> bugeye
> > > > with a generator?
> > >
> > >
> >
> >
> 


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