Date:         Thu, 15 Jul 2004 17:54:37 -0700
Reply-To:     mark drillock <drillock@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark drillock <drillock@EARTHLINK.NET>
Subject:      Re: Low voltage
In-Reply-To:  <6.1.2.0.0.20040715164315.02a226b0@mail.gct21.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Doing this to a Vanagon entails risk not encountered in the Volvo. The
Vanagon ECU is wired nearly directly to the alternator output. Sensing
the voltage much farther downstream opens up the possibility that the
ECU can see a much higher voltage than intended and for sustained
periods. If the charging path from the alternator to the battery should
be disrupted the ECU may see unregulated alternator output and be
damaged. This is already a  failure prone area of the Vanagon wiring so
the chance of this type of failure is significant. Fix the wiring and
replace the weak charging components as needed instead.  Add another
wire from the alternator to the battery or dash even.

I know that Steve is capable of determining the condition of his wiring
and charging system so that any risk is minor. Most people here are not.
Most people here should not consider major changes to their charging
systems without competent supervision.

Mark

Steve Delanty wrote:

> Fin,
> The stock internal regulator in the Bosch alternator is lazy as
> hell and doesn't keep very good regulation. To make the problem
> worse, it measures the voltage right at the alternator instead of
> at the battery, so voltage drop across the wire from alternator
> to battery compounds the "droopy voltage" problem at high load.
>
> You can disable the internal regulator and use an external
> Ford style regulator instead. The ford regulator not only woks
> better, but it has external voltage sense wire, so it can measure
> the voltage right at the battery instead of back at the alternator.
> (you need to run a small wire from alternator to battery for this)
> I performed this conversion back when I still had a WBX, and
> it made a great difference in battery voltage under a heavy load.
> Mine was rock stable at around 13.8 volts under most any load.
> It also made my headlights brighter, and my fridge work better
> on 12 volts......
>
> It's a common enough conversion amongst Volvo owners. I don't
> seem to have a link handy, but Google with keywords "bosch
> alternator" ,"ford regulator", and maybe "volvo" and you should
> find instructions on how to perform the conversion...  it's pretty
> easy and works *great*.
>