Date:         Wed, 20 May 2009 12:09:46 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Short-finding technique was Re: Electrical help please!
Comments: To: Aaron Robinson <a.robinson.lists@GMAIL.COM>
In-Reply-To:  <a38639ed0905192006g7968dc92pc8c559b232c4aeea@mail.gmail.co m>
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At 11:06 PM 5/19/2009, Aaron Robinson wrote:
>So here are my questions:
>1) Any tips on troubleshooting the wipers?
>2) Any tips on troubleshooting the fuse issue?

Here's a technique that can be useful in finding shorts:  Wire up a
stoplight bulb or other load in place of the fuse that's
blowing.  Now probe the circuit downstream of the lit bulb with a
meter on millivolts scale, looking for millivolt differences in
voltage to ground.  Each time you find a lower reading, follow that
path.  When the reading stops decreasing you've found the short.

The sensitivity of this technique increases proportional to the
current flowing in the circuit, so the heavier the load the better up
to the rated capacity of the circuit.

This hasn't been discussed much here because opens are far more
common in our vehicles than shorts.


  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"