The original requestor pointed out privately that he's certain this is an
alternator, not a generator. These instructions do not apply to him.
Phil Roettjer wrote:
>
> The only thing you need to do to use a positive ground generator in a
> negative ground application or visa versa is to make sure the field winding
> is polarized correctly. To do that momentarily touch either +12V or -12V to
> the field connector (smaller of the two connectors). For a negative ground
> system you touch +12V, or you touch -12 for a positive ground system. You
> should always do this anyway when installing a new generator since you don't
> know which way it had been polarized. Neglecting to perform this operation
> causes a large current spike the first time you turn on the car which can
> cause damage to the voltage regular, ammeter, etc.
>
> Good luck!
>
> -----Original Message-----
> From: Simon Favre [mailto:simon@mondes.com]
> Sent: Wednesday, May 02, 2001 7:23 PM
> To: Paul
> Cc: Vintage Race
> Subject: Re: Positive ground alternator?
>
> Are you sure it's an alternator? 1964 sounds like it should be a generator.
> If you know some basic electronics, and have the right schematics, you can
> use a negative ground generator to produce positive ground current, and
> vice versa. A generator doesn't know the difference. In the usual generator
> circuit, it's the generator light that "polarizes" the generator. Anything
> else is hocus pocus. The regulator and the generator are usually matched to
> each others max ratings, so mixing and matching brands there can be
> dangerous. I used to have a Lucas generator (positive ground) happily
> putting out negative ground in an Alfa Spider that also didn't care which
> polarity it was fed.
>
> Alternators are polarized by the way the diode chassis is mounted, and they
> are all negative ground, AFAIK. There is no easy way to change the polarity
> of an alternator.
>
> Simon
>
> Paul wrote:
> >
> > I'm looking to replace a positive ground alternator in a 1964 Datsun
> 1500.
> > Since Datsun never brought too many of these little cars in to the states,
> > finding parts is rough. Does anybody know of another car that was
> imported
> > that used a positive ground alternator? I seem to remember burning up one
> > in a 1970 Ford Cortina by wiring it backwards to the battery. Were they
> > positive ground or is my memory finally gone too!
> >
> > Paul
> > Ohio Roadster Owners Club
> > Sloan Racing
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