Mark,

  Did you happen to have taken photos of the conversion process?

 

Kelly Troyer
--
Dyke Delta/13B/RD1C/EC2

-------------- Original message from Mark Steitle : --------------
> At 11:34 AM 6/15/2004 -0700, you wrote:
>
> >Hi Mark;
> > I'm looking for an alternator also. would appreciate
> >your external alternator wiring info.
> > Thanks John Overman
> > Velocity RG
> > 13B Turbo
> > Washington State
> John,
> Here you go...
>
> =============================================
> Bob N. strongly recommends using externally regulated alternators only, or
> modifying the internal regulator models so as to allow it to be shut down
> if necessary. (Supposedly, a voltage run-away can happen in a few seconds.)
> Problem is that the articles I read explaining how to convert the
> internally regulated alternators to external regulation didn't work. (Did I
> do something wrong?) I think I have worked out a simpler solution. The
> objective here is to isolate the field windings from the diode bridge so
> that the alternator can then be externally controlled.
>
> This is how I went about converting my alternators. First I removed the
> back cover, exposing the diode bridge, regulator assy. and brush holder.
> Then removed the regulator and brush holder and threw the regulator assy in
> the trash.
>
> Next I removed the brush holder and shaped a little brace from
> 1/8" phenolic that will support one side of the brush holder and isolate it
> from the diode bridge. This piece will be about 7/8" x 1/4" with a #8 hole
> in each end. Do not make this piece out of metal or it will short out the
> diode bridge. Also make up a jumper wire about three inches long with a
> ring terminal on each end. One end will attach to the right terminal on the
> brush holder and the other will attach to the alternator case (gnd.).
> The other terminal on the brush holder will need a spacer under it to keep
> everything aligned properly.
>
> The left brush will need to have the lead wire
> un-soldered from the brush holder. The wire comes through the back of the
> brush holder. Unsolder it there and drill out the hole just a bit to allow
> a #20 wire with shrink tube to fit snugly through the hole. Solder the #20
> wire to the end of the braided wire on the brush.
>
> Now we're ready to reassemble the whole thing. Pass the #20 wire through
> the hole drilled in the brush holder and reinsert the spring and brush.
> Screw the brush holder back into place, with a spacer washer under the left
> terminal. The ground wire goes on the opposite terminal. Feed the wire
> soldered to the brush through a hole in the alternator cover, with a
> grommet to prevent chaffing. This wire will go to the "F" terminal of the
> external voltage regulator. I used a generic Ford unit from a mid-seventies
> model (approx. $10/ea from Auto Zone). The S & A terminals of the regulator
> tie together and get fed from the alt. switch & 5 amp breaker. The "B"
> terminal on the alternator goes to the battery contactor. The other
> terminal on the regulator isn't used.
>
> I modified two ND alternators using this method and they both work great.
> It takes about 30 minutes to do the modifications. All I need to do now is
> add a crowbar over-voltage protector to each regulator and I'm set to go.
> Or you can use a B&C voltage regulator with built-in OVP and low-voltage
> warning.
>