Date: Sat, 9 Aug 2008 13:26:18 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Bentley wiring typo?
In-Reply-To: <489DF279.3090207@cox.net>
Content-Type: text/plain; charset=ISO-8859-1
Ah ok. 50 is a ground that is positive only when starter cranking.
Thanks much Mark. It didn't make sense looking at *just* the relay diagram.
I saw your "hard start relay" warning in the archives. This led me to
rethink the "coil" relay I installed in my Jetta conversion. It is
grounded to frame, triggered "on" by Vanagon 15 wire in engine bay and
carries B+ from 30 to a larger gauge ignition wire used by the Jetta
coil.
My Vanagons coil wire is a smaller gauge. IIRC, it was you that kindly
suggested this work around.
I was going to install a fridge relay to cure another problem: the
engine sometimes doesn't shut down with the key. With key "off", I
pull the hand brake on, it shuts down.
But.....
I have the aux battery relay wired like this:
B+ starter battery: 30
Aux. Battery B+ : 87
Blue alternator: 85
Frame ground: 86
Maybe i need to "ground" 86 to 50.
Maybe this would cure my "handbrake on to stop engine" problem (?)
(though this doesn't seem to happen when engine driven at temp for
more than 20 minutes)
Neil.
On Sat, Aug 9, 2008 at 12:39 PM, mdrillock <mdrillock@cox.net> wrote:
> My Bentley does not have that page but the wiring diagram sounds right.
>
> It may be a confusing oddity but VW often 'grounds' the fridge relay coil
> with the wiring connection to the starter motor coil. The voltage from the
> alternator blue wire triggers the fridge relay on whenever that voltage
> finds a path to ground on the other leg of the relay coil. This means that
> during normal operation a small amount of current is always flowing through
> the starter coil from the fridge relay coil. Not enough to actuate the
> starter by a long shot but a possible issue for some as I mention below.
>
> This is not a true ground but it is an effective one. It also adds another
> level of certainty to turning off the fridge relay during starting. During
> starting this pseudo ground becomes a positive voltage and disables the
> fridge relay regardless of the charging status of the alternator.
>
> They did not do this on the fridge relay of all Westy models and there is no
> strong reason for you to do it this way now. They used this same method with
> factory aux battery relays and it makes better sense for that one.
>
> (This use of the starter coil as a pseudo ground causes a big problem if
> someone tries to add a 'hard start relay'. The added starting relay can be
> triggered on by the voltage passing through the fridge relay and this will
> engage the starter motor while the engine is already running. The solution
> for this is to unplug the wire from the fridge relay that goes to the
> starter circuit and add a simple ground wire between that relay leg and the
> relay mounting screw)
>
> Mark
>
>
>
> neil N wrote:
>>
>> Hi all.
>>
>> I'm sorting out my hand brake "turns off" engine issue. Dennis Haynes
>> kindly wrote and indicated a lack of a fridge relay might the problem.
>> I'll connect the fridge relay from my 182A downstream from the blue
>> wire to aux battery relay to see if it helps.
>>
>> I'm using the '81 camper wiring diagram, but in checking "camper"
>> wiring, I'm curious about 97.32e of Bentley.
>>
>> It shows "to ignition/starter switch terminal 50" from 85 and "To
>> alternator terminal D+" from 86.
>>
>> Does the ground for the relay coil come from the case of the relay?
>>
>> I only have a 182A fridge relay in hand. (plastic case)
>>
>> Just curious.
>>
>> Thanks,
>>
>> Neil.
>>
>>
>>
>> --
>> Neil Nicholson '81 JettaWesty "Jaco
>>
>> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>> http://web.mac.com/tubaneil
>> http://tubaneil.googlepages.com/
>>
>>
>>
>
>
>
--
Neil Nicholson '81 JettaWesty "Jaco
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/