Date: Fri, 6 Mar 2009 06:49:45 -0800
Reply-To: mark drillock <mdrillock@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: mark drillock <mdrillock@COX.NET>
Subject: electrical plumbing- was dash gremlins
In-Reply-To: <4d1b79350903020847q368bc101i795311280232baea@mail.gmail.com>
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I lived in an old house once, it had some plumbing problems. The shower
drain was very slow so you could only run the shower on very low unless
you wanted to be standing in water. Eventually I got around to fixing
the slow drain. Right away another problem popped up with the shower.
All of a sudden if someone flushed the toilet the shower would change
temperatures in an annoying way. Never did that till I fixed the drain!
Did that mean I messed up trying to fix the drain? Of course not. All it
meant was that a second problem existed inside the fresh water pipes.
Once the shower could be run at a normal flow and still drain ok, the
shower was suddenly using more water. This left less cold water for the
toilet tank to fill with. Then when someone flushed the water was split
between the filling the tank and running the shower. Of course the
problem was not the shower or the toilet themselves, but rather a
constriction in the water pipe feeding the whole bathroom.
Electrical gremlins can manifest themselves in this same way. Our vans
are getting to be 20-25 years old. They all likely have small problems
creeping into the electrical system. We see this on the list all the
time. The oldest vans not only have had more time to develop problems
but they also have some design weaknesses that VW addressed in later years.
The plumbing example above is directly related to the kind of gremlins
people see in the dash electrical systems. Fixing one problem may cause
a new symptom to pop up or an old symptom to change. This confuses
people because they don't understand much about electrical systems. The
grounds are like the drain pipes in plumbing. The capacities of the
drains have to be equal to or larger than the fresh water sources or
there will be backups. Likewise the fresh water pipes need enough
capacity to run all of the adjacent fixtures at the same time or at
times there will be lower flow than is needed.
Mark
Jim Felder wrote:
> I know my wiring is trying to tell me something. If I could only
> figure out what... will keep thinking and poking around.
>
> Jim
>> I'm sure that you think just the opposite but the new turn signal led
>> behavior since you strengthened the cluster ground in fact points to where
>> the real fault likely is.
>>
>> Mark
>>
>>
>> Jim Felder wrote:
>>> Three-year-long story short: No turn signal indication on the dash,
>>> other than the relay clicking. Over this winter, on cold days, temp
>>> needle went nuts and temp LED flashed until car was warmed up.
>>>
>>> Replace the temp "relay" and the temp needle calmed down for good, it
>>> always operates properly now--which is strange, because I wam told
>>> that the relay controls the light, not the needle.
>>>
>>> At first the blinking light would not quit and as the car warmed up,
>>> this blinking because so intense that for all practical purposes the
>>> light was always on at normal temps.
>>>
>>> Then this quit, and my turn signal indicator light started working for
>>> no apparent reason as long as the headlights were off. If they were
>>> on, no turn signal indicator light.
>>>
>>> Sooooo, I thought to myself, "very good, better anyway, but you
>>> haven't done anything to improve the grounds.
>>>
>>> So I did as Mark D. and other suggested and cut the two brown wires to
>>> the big connector and soldered them to a big common ground wire with a
>>> ring, and put that under the big screw supporting the heater lever
>>> assembly. I soldered the two "tail" ends together.
>>>
>>> Now I get this: no turn signal indication under any circumstances, and
>>> the temp LED blinks unless I cycle the key on and off a few times to
>>> kill it.
>>>
>>> Jim
>>>
>
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