alt problems

[scirocco16vr32 at gmail.com (Chris Bennett)]

Julie, my car does something similar.
 When I start it I get a battery light on the dash until I rev it up a 
little. This can be the sign of a voltage regulator going bad--or even bad 
windings on the alternator. 
 It is my understanding and please someone correct me if I am wrong is that 
the primary difference between an alternator and a generator is that the 
generator has permanent magnets in it and the alternator has TWO sets of 
windings. One that gets generates a magnetic field by passing current 
through it (from the battery I suppose) and this would replace the perm 
magnets in a generator. AC is generated by passing a coil through the 
previously mentioned magnetic field. AC is then passed through a bridge 
diode pack in the voltage regulator to produce DC at 12v (14v actually isn't 
it to charge the battery?) Now if the coils are going or that bridge 
rectifier are going then you would need a higher RPM to produce the same 
amount of DC. 
 Either case unless you want to disassemble the alternator for the diode 
pack (which is actually fairly easy to remove) you may be better off getting 
a new alternator. Alot of places have lifetime warranties now. You may want 
to "upgrade" if you don't already have a 90 amp alternator. 
 This may be as simple as a loose belt or a bad ground...
 Full of useless info,
Chris

 On 5/17/05, George Herndon <gherndon@eyeontech.com> wrote: 
> 
> julie,
> 
> i was reading up on doing an alternator swap yesterday. i read that
> there is a sending wire (blue, maybe) that sometimes breaks.
> apparently the alt are designed to "engage" and charge with
> sufficient rpms, so you are noticing this engagement. check the
> bentley for the specific sending / activation wire, but i think this
> is the problem.
> 
> can't find yesterday's link, but you can probably google a match.
> 
> -george
> 78 champagne edition
> charlotte, nc
> 
> i need vent windows
> 
> On May 17, 2005, at 12:09 PM, scirocco-l-request@scirocco.org wrote:
> 
> > Message: 9
> > Date: Tue, 17 May 2005 16:04:35 +0000
> > From: "Julie Macfarlane" <juliemac57@hotmail.com>
> > Subject: Alt problem?
> > To: scirocco-l@scirocco.org
> > Message-ID: <BAY103-F27D5E276F1D1B3D678A256DD160@phx.gbl>
> > Content-Type: text/plain; format=flowed
> >
> > When I start my car I have to rush the engine to get the alt to
> > kick in.
> >
> > Whats up with this?
> >
> >
> >
> > Julie Macfarlane
> > "Its not just a car! Its an adventure!"
> > 1981 MKI 2L 16v w 2Y
> > Amsterdam NY
> >
> 
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