Date: Sat, 9 Aug 2008 15:09:42 -0700
Reply-To: mdrillock <mdrillock@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mdrillock <mdrillock@COX.NET>
Subject: Re: Bentley wiring typo?
In-Reply-To: <c4e7c5f90808091326t6c68ccc4n2402d3c91b4f7867@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Neil, before changing anything in your wiring I would suggest you try to
track down the exact source of this run-on problem. Next time you have
it still running after the key is off try unplugging the small blue wire
at the alternator. You may need to put in a longer wire there to enable
you to do this safely. The wire would be just for this testing and not
permanent.
If this stops the engine then you can modify the circuit to correct the
problem. The root of this problem is likely the relay you added to power
the ignition coil. The added relay's coil takes so little power to hold
it active that just the feedback voltage from the alternator warning
light circuit is enough to keep it closed and the engine running. Then
when you pull the parking brake handle the brake switch connects the
brake warning light to the same circuit which adds a small additional
load that is enough to drag down the voltage and release the relay. I
believe it is as simple as that.
There are a number of approaches to correct this but the first step
would be to measure how much current is actually flowing through the
power side of the added relay. If the current is low enough you could
just remove it and let the stock black wire do the job alone. Or you
could add a heavier wire from the ignition switch to do it alone. You
could add a diode to the cluster wiring so the current can't flow
backwards through the activation resistor for the alternator blue wire.
Mark
neil N wrote:
> 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.
>
>
