Re: 200TQ dash light problem

["Fred Munro" <munrof@isys.ca>]

Hi Michael;

    Aha; you have pinpointed your problem! A bad connection at this
grounding block will cause the symptoms you have observed. The pins are
soldered to the inner (speedo) board and the green "jumper block" is
soldered to the outer (IP lights) board. When the boards are assembled, the
pins enter the jumper block and make the ground connection between the inner
and outer boards. You can have a problem with the solder joints or a problem
with the "jumper block" contacts. Either way, you get an intermittent ground
which causes the lighting problem you have observed.
    There are two of these grounding blocks - I think a fault at either one
will give you similar symptoms.

HTH

Fred Munro
'91 200q  262k km
-----Original Message-----
From: Michael Skowvron <michaels@pittsburgh.sgi.com>
To: quattro@coimbra.ans.net <quattro@coimbra.ans.net>
Date: Sunday, November 08, 1998 4:08 PM
Subject: 200TQ dash light problem


>I have been experiencing intermittent lighting problems in the
>instrument cluster of my 200TQW for quite a while now.  Occasionally,
>the two lamps nearest to the middle which light the trip computer and
>the edges of the tach and speedometer will go dim and at the same time
>the two turn signal lights and the high beam indicator light dimly.
>It looks like a grounding problem since it can be fixed by driving
>over a bump or giving the top of the dashboard a smack.  I have been
>living with the problem.
>
>Last week, the ignition swith broke, so the whole dash assembly had to
>be removed.  I took the instrument cluster and bagan to disassemble it
>to look for the problem.  I may have found the problem, but I'm not
>sure, so I'm looking for some help.
>
>When I measure the resistance from one of the dash lamp connections to
>one of the turn signal connections, I get 16ohms.  If I flex the
>circuit board a little bit, the resistance drops to 4ohms.  I traced
>the intermittent connection to two pins that stick up through the
>board at the upper right above the speedometer.  This is very near to
>a 28pin black connector.
>
>These two pins are capped with a small green insulator that looks like
>a jumper.  The two pins pass through the curcuit board to another
>circuit board that is part of the speedometer.
>
>I don't know if these pins are supposed to be making contact with the
>back circuit board or not.  The back circuit board moves freely and is
>not making a good connection to the pins.  But there are sloppy solder
>joints on the bottom of the board which make it look like they are
>supposed to be connected!  By wiggling the pins, I can make and break
>the connection.  For additional information, if these two pins were to
>be connected to the back circuit board, they would trace their paths
>to pins 10 and 11 on the black 28pin connector that is above the fuel
>guage.
>
>Here's where I'm confused.  I can't understand how this was assembled
>in the first place.  The solder joints are on the side of the board
>thats "inside" the sandwitch.  The white plastic piece that covers the
>whole circuit board also covers the solder joints.  The pins pass
>through the white plastic and then through the back circuit board, but
>there is no way to get at them and re-solder them!  If they were
>soldered at one time, then the back circuit board would not separate
>from the white plastic piece because of the solder connection.
>
>What do I do?
>
>Michael
>