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Subject:Re: digitool readings help needed
From:David Beierl
Date:Wed, 12 Jun 2002 14:48:47 -0400

At 01:16 PM 6/12/2002, Ed DeBolt wrote:
>guess that leaves grounds as the issue. Is there a particular ground that
>would be the likely culprit

I doubt if it's much of an issue (certainly not for O2 sensor, though I
can't promise for other things).  The Digitool takes its ground reference
from inside the ECU.  Since the ECU hangs on the end of a wire and draws
power, it is a guarantee that its internal ground point will be higher than
the battery ground, since there is always some voltage dropped across the
wire and connections.  I doubt that two-tenths of a volt is a problem here.

But you're encouraged to go out with a voltmeter set on millivolt range and
measure voltage drops along wires, between alternator and engine case,
across connectors etc. -- the results will certainly be interesting and you
will very likely find some situation somewhere that should be
corrected.  Use sewing needles to pierce the wire insulation, they have
such fine tips that the hole seals right up afterward.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"