Date: Sat, 12 Apr 2003 10:18:27 -0700
Reply-To: Shawn Wright <swright@ZUIKO.SLS.BC.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Shawn Wright <swright@ZUIKO.SLS.BC.CA>
Subject: Re: Vanagon Syndrome
In-Reply-To: <5.1.1.6.0.20030410062207.00a89660@mail.gct21.net>
Content-type: text/plain; charset=US-ASCII
On 10 Apr 2003 at 7:34, Steve Delanty wrote:
> I'm certainly not a digifant expert, and I've only owned a vanagon
> a couple months, but I'm not a stranger to electrical troubleshooting
> and based on a bunch of hours with a scope and VOM peering into
> the engine hole, and from what I've read on the web, here's MY
> OPINION about vanagon syndrome.... FWIW
>
> I think that "vanagon syndrome" can be caused by a wide range
> of things, all of which confuse the AFM until it blows it's mind.
> A quick key-off reset clears it's mind and all is well... until next time.
>
> It's also my opinion, from all I've read on the web, and from my
> own testing that a large percentage of the time this is caused
> by flaky electrical connections and especially by insufficient
> grounding. Many folks have apparently fixed their problem by
> finding and repairing a missing/broken/loose/corroded ground
> connection. The 2 flat ground braids, one on the left side head
> and one on the nose of the tranny are the 2 major ground points
> between the engine and body and MUST be clean, tight, and in
> good condition.
Steve,
I did the capacitor fix and extra ground from the AFM a few years ago, and it seemed
to make no difference also.
<snip>
> So. After my findings with the oscilloscope on the engine ground I
> did 2 things. First, I added a noise supression capacitor on the
> back of the alternator. This capacitor is stock equipment, but they
> have a tendency to disappear with time, as people forget to put
> them back on during an alternator replacement. Mine was missing.
>
> I don't know the value for the stock capacitor, but I used 0.5 uF
> 250 volt ceramic disc capacitor on mine. Or you can goto the
> FLAPS and buy one for almost any make and model of car
> and it should work fine. Even the condenser from a points type
> distributor will work good. These are typically 0.25 - 0.5 uF at
> a couple hundred volts.
>
> The capacitor connects from the + output stud on the back of
> the alternator to one of the ground studs on the alt.
My alternator appears to have only one ground stud, right beside the larger + stud. Is
this normal? I don't have a capacitor, so I will search my electrical junk for a suitable
one.
> The second thing I did was to add a #2AWG wire directly from
> the back of the alternator to the body at the front of the engine
> compartment, well away from the stock ground points on the
> left side. This gives the alternator charging current a nice direct
> path to the body of the vehicle and reduces the current thru the
> stock ground braids, which helps reduce the DC voltage drop
> problem I was seeing across the stock flat braid.
I assume you're suggesting using the ground stud again here? Mine seems rather
small, so I'm not sure a #2 wire connector will fit. It appears around an M6 size stud.
Any ideas on a good place for grounding to the body on the right side? I'd rather not
drill if I can avoid it. I was thinking there must be a bolt on the frame somewhere I
could use. I could not see anything obvious when I looked today, at least not within
the engine compartment.
Shawn Wright, I.T. Manager
Shawnigan Lake School
swright@SLS.bc.ca
http://Zuiko.sls.bc.ca/swright
http://www.sls.bc.ca
| 
