Date:         Thu, 13 Dec 2001 16:09:24 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: 2nd battery relays & the Hella in particular
Comments: To: Tim Hannink <tjhannink@EARTHLINK.NET>
Comments: cc: pensioner <al_knoll@pacbell.net>
In-Reply-To:  <20011213204015.17531.qmail@earthlink.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 03:40 PM 12/13/2001, Tim Hannink wrote:
>wire installed between pin 30 of the relay and the positive terminal of
>the auxiliary battery. The relay is P/N 411 915 511B and the drawing on
>the side shows an internal diode connecting pin 85 and the solenoid. A
>green 18 gauge wire connects to pin 85, I haven't traced out where it goes.

Ok, that agrees with Bentley 97.34a/b except for wire color and the
different sizes to and from the relay.

The diode is to prevent the relay from activating during cranking.

But now I'm *really* scratching my head over the precisely similar setup
for the fridge relay.  By this reasoning it should have an internal diode
as well -- maybe it does (Al?) though it doesn't show on the
schematic.  Nor can I find the relay in ETKA.

I really think that VW's grounding the relay control terminal through the
starter solenoid is excessive complication to little purpose.  If there's
someone who truly understands the reasoning could they please 'splain it to
me?  I thought I did, once...still think I do, I guess, but all this effort
to prevent something that isn't going to happen (the alternator starting to
charge while the engine is cranking) really puzzles me.  What am I missing?

david


David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"