Date: Sat, 9 Aug 2008 15:45:45 -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: <489E15A6.3070207@cox.net>
Content-Type: text/plain; charset=ISO-8859-1
Mark.
Awesome info and great suggestions.
I just added a fridge relay downstream of the aux battery relay. It
would have been there in the stock configuration and if I keep my
Dometic 182B (dang thing still goes out randomly!) I would hook up the
12V eventually. Regardless...... I'm sure you're right. The added
relay is likely staying closed. This makes the most sense.
The detail about the added relay was something I'm not sure I posted
when originally asking this question.
The good news is that I know the exact route to drive to get it to
malfunction. I will do this. If the problem still exists, I will do as
you say. I wasn't sure if pulling the blue wire with engine running
would do harm. Good to know I can pull it with engine running to test
things.
I checked for voltage (drops?) at grounds on "stars" above the fuse
box. Nothing there. And no voltage when measured at the brake warning
light ground(s).
I too had thought to run a heavier gauge wire from the ignition switch
so the wiring remained stock, but it would be good practice to learn
how to measure current flow and see (thank you internet) if the
existing wire is sufficient.
And thanks for explaining so well, what I was just starting to
understand. I figured the load of the brake warning light was the
reason. Just didn't know exactly why.
Again, really appreciate the direction/explanations.
I'll post what happens to the list, along with some droll info about
solving the poor acceleration/power issues I was having, soon.
Cheers,
Neil.
On Sat, Aug 9, 2008 at 3:09 PM, mdrillock <mdrillock@cox.net> wrote:
> 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.
>>
>>
>
>
>
--
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/
