Date: Fri, 16 Dec 2005 11:28:54 -0500
Reply-To: The Bus Depot <vanagon@BUSDEPOT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: The Bus Depot <vanagon@BUSDEPOT.COM>
Subject: Re: Could hot starting problems be caused by a defective ignition
swich?
In-Reply-To: <8C7D0699F4C81A4-1840-CC8D@mblk-r16.sysops.aol.com>
Content-Type: text/plain; charset="us-ascii"
> He has a HOT START PROBLEM , not a NO CRANK PROBLEM.
He did not specify whether the starter was actually cranking or not (except
sometimes after releasing the ignition key). The solenoid issue (which
would result in a no-crank problem) is commonly referred to on air-cooled
VW's as a "hot start" problem.
> A Nobel Prize is in order here because Ron has
> unearthed a metal which CONTRACTS with temperature.
Okay, you got me there; I was writing at midnight, not proofreading, and
thinking stupidly. :-) It is the solenoid expanding, not the sleeve
contracting. But the net result is the same; reduced clearance between the
two causing the solenoid to require more current to kick.
> If the starter's current draw were routed through the
> ignition switch, then the ignition switch would be the size
> of a three pound Maxwell House coffee can.
Since the early Bus, VW has always routed the starter solenoid's current
through the ignition switch rather than using it as a trigger. This causes
problems on many Busses (where the battery is practically next to the
starter, so the current feeds from the battery in the back of the Bus, all
the way to the ignition switch up front, and then back to the starter in the
back). It is less common with Vanagons (perhaps because of the shorter
signal path, the battery being closer to the ignition switch; perhaps
because many Vanagons are newer and have not suffered as much
wiring/terminal degradation yet), but it is still not unheard of. The "fix"
of using a relay or similar solution to shorten this path is nothing new. It
dates back about 25 years, to John Muir's "How to Keep Your Volkswagen
Alive," and has been a widely used remedy ever since.
> Anyway, why cover the symptom with a
> Band-Aid instead of curing the disease?
That's a reasonable question. There are two lines of thought on this, which
is why I mentioned both alternatives. It depends on whether you consider
adding a relay a "band-aid" approach, or an improvement over an
intrinsically flawed original design. Proponents of the relay approach
would suggest that the stock design is silly and makes the starter far more
prone to minor voltage drop than it needs to be. Therefore, shortening the
path makes it less prone to this problem by eliminating the original design
flaw. Detractors of the relay approach would contend that if there are
corroded terminals, etc., there may also be voltage drop that is affecting
other things (i.e. headlight brightness), and the hot-start solenoid failure
is a warning sign of a larger looming problem. Therefore it should be
resolved by cleaning/replacing all of the contacts (and perhaps the starter
or solenoid if all else fails). Frankly I make more money selling $100
starters than $15 relays, so from a profit perspective I should not be
suggesting a cheap relay fix. But from a "real world" perspective, many
people over 25 years have elminated the hot-start issue problem by simply
adding the relay. Of course this really is not an either/or proposition. You
could inspect/repair all connections and also add a relay for good measure.
After all, while a hot-start solenoid problem may be an early warning sign
of a more global voltage drop issue, this "warning sign" can leave you
stranded if it causes the starter not to turn at an inopportune time.
Therefore, as warning signs go, it can be a rather inconvenient one.
- Ron Salmon
The Bus Depot, Inc.
www.busdepot.com
(215) 234-VWVW
_____________________________________________
Toll-Free for Orders by PART # : 1-866-BUS-DEPOT
>
Damn, and
> I was so close in thinking that the slug of the solenoid
> expanded with heat soak and that, along with the gummy ca-ca
> which forms in the solenoid over a period of time, causes the
> slug to stick.****
>
>
> We also sell an inexpensive relay kit, part # WR1, which
> can often solve this symptom in a different manner; it
> shortens the signal path by providing a direct feed from
> battery to starter (using the ignition switch merely as a
> trigger, rather than sending the starter's entire current through it).
>
> - Ron Salmon
>
>
> ****To answer the question posed by the original poster:
> yes, a defective ignition switch could cause an intermittent
> open in the IGNITION circuit.****
>
> ****George****
>
>
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