Date:         Wed, 9 Sep 1998 20:10:37 -0700
Reply-To:     Lawrence Dongilli <buspilot@WORLDNET.ATT.NET>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         Lawrence Dongilli <buspilot@WORLDNET.ATT.NET>
Subject:      Headlight Switches and Electrical Fires
Comments: To: Vanagon@VANAGON.COM
Content-Type: text/plain; charset=ISO-8859-1

> BTDT, congratulations, you have just aquired a melted headlight switch.
> The good news is that any pre 80 rabbit or scirocco has the same switch
or
> you can shell out about $25 US from one of the discount parts places.
Buy
> two switches as I have killed two in the last year.  The last one was 1
> hour from home at 2am!


It is not normal to go through two light switches in one year.  It is wise
to find and fix the problem rather than to keep throwing switches at it,
else the problem may bloom into something much more serious.

If you are melting headlight switches, I would suggest checking/replacing
the crimped terminals on the wires that lead to the switch.  I suspect a
slight bit of resistance has developed over the years (a bit of oxidation
is all it would take) and is heating up with the hight current load.  You
may be able to feel the heat when the lights are on if you touch around the
connector.  I just encountered similar problems with the air conditioning
wiring a little ways back (mentioned in an earlier post).  Connections
getting _really_ hot.....but not along the length of the wire.  Replaced
the terminal (crimped and soldered)......like magic I got a cool
connection.  Did them all this way.  Worked wonders.....night and day.

 _All_ of your crimped connections are vulnerable to some degree....but the
high current circuits are the ones that are going to get hot.  I am not
talking about 'a lot' of resistance either.  A connection with one half ohm
resistance on a 20 amp circuit can dissipate 200 watts!  It is gonna get
hot!   Please check your connections.....I cannot stress this enough!

Also, if you are using older used switches, it is possible to encounter
higher contact resistance from normal wear and tear.  Over time, the
contact surfaces can also oxidize from all the normal arcing and micro
welding present.  Just be aware.

By the way, I just got some sensor terminal samples from 'Amp' Corp.  They
make all sorts of electrical contacts, connectors, etc.  They are _huge_.
I bought a couple of replacement female sensor contacts (for use in
injector, O2 sensor, temp sensor and other connectors in the engine
compartment) from the VW dealer to use as a reference, and did some
research.  I found a match!  The newer style contacts from the dealer are
much better than the original style, as they have a much higher insertion
force (due to an additional external clamping 'spring') _and_ gold plating
on the contact face.  Very nice.  They will stand up much better to years
of heat and vibration.  The dealer charged me something like $1.57 each for
them, but I think Amp wanted only $0.15!  It was interesting to note that
these particular parts came from Amp of Germany.

I am going buy a bag and get to work.

Lawrence