Voodoo speedometer repairs

[rmyers@olie.wvitcoe.wvnet.edu (Robert Myers)]

Dan,

This one might be worth putting into the FAQ.

--- use your virtual scissors here --- save the bottom part-----

While this post may be premature, I'm so delighted with the preliminary
results that I just have to share this report with the list.

Starting over a year ago my speedometer has been acting very flaky
intermittently.  Many bucks (too many - but that's the subject of another
post) were spent with my fiendly (sic) [yes, I meant to spell it that way]
Audi dealer in fruitless attempts to repair the problem.

Perhaps the source of the problem and a solution to it have been found.
After removing the instrument cluster from my '89 200TQ (for the Nth time.
This now takes me about 3 minutes flat.  :-( ) and disassembling it far
enough to remove the printed circuit board and the speedometer head itself,
I was testing various connections for continuity.  Everything checked out OK
with the DMM.  However, while testing continuity between the four pins from
the speedo head itself and the pc board I noticed that there seemed to be a
bit too much flex of the pins inside the connectors to the pc board.  Could
this slop be the source of the intermittent circuit break?

The trial remedy I finally hit upon was to insert another wire into the
connector with the pin to tighten it up.  Lacking a convenient piece of
copper wire of the right diameter, I got four small straight pins from my
wife's sewing supplies and fashioned four L-shaped pointed pin pieces by
cutting off the points of the pins and bending them into an L shape about 6
or 7 mm from the point.  This left a 2 mm or so end bent over to act as a
handle when and if I ever need to remove them.  I simply forced these pins
into the four connectors along with the pins from the Speedo head.  This
tightened the mechanical fit between the pins and the connector.

Reassembly of the IC (make sure that the ends of the pins are oriented so
that there is no possibility of them shorting to each other) and then
replacing the IC in the dash and presto!  Instant working speedometer.
Using straight pins!  :-)  Thus, a voodoo repair.  :-)  Hmmmm.  Wait a
minute.  Voodoo involves sticking pins in a doll.  This was more like
acupuncture.  These pins went into the actual object.

Anyone have a good doll of an Audi service manager?

At the moment, the speedometer is still working.  Mike LaRosa's speedometer,
fixed using the same technique, he tells me, is also working.  For how long?
Well, the jury is still out.  There will be another post in a few months (or
sooner if the problems return).

Many thanks to Steve Bucholz and Mike LaRosa for their advice and support
and encouragement and ideas and to all the others who have been so
supportive with their suggestions and encouragement .  Thanks fellas.  :-)

Bob
   **********************************************************
   *  Robert L. Myers  <rmyers@olie.wvitcoe.wvnet.edu>      *
   *  Chair, Department of Chemistry, WVIT                  *
   *  Home:(304) 574-2372        Office: (304) 442-3358     *
   *  Obligatory references for Quattro and Sleddog Lists:  *
   *       My Huskies like to ride in my '89 200TQ.         *
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