speedo jumping

[Swann, Benjamin R. (BSWANN)]

[Dave Hord wrote and Huw responded:
>
> I've searched the archives, and found the question asked a pile of
times..but I
> can't find the answer!!
>
> What do I do to fix the speedometer needle jumping around in my 1989 90
quattro?

if its not the sender at the tranny or the connector there, try
dismantling the cluster and checking for bad solder joints, etc., clean
and reassemble.

fixed my flaky clock problems that way.
--
Huw Powell]

Dave,

I know this question has been addressed a number of times, and should be in
the archives. Try searching on..  bobbing speedo - Speedometer Fix; 5KCSTQ
speedo intermittent.

Here it is once again..in short(no pun intended) - resolder aged solder
joints.

Followup Speedometer/Instrument Guage Repair:

I fixed my speedometer on the '86 5000 CSQT ('87 was the same) following
some great advice from (thanks!) Alan Cordieros: "The problem is almost
certainly in the solder joints that hold the pins which make the connection
from the guage into the green flex circuit board on the IC(instrument
Cluster).

Pull the speedo guage out from the cluster, this takes a lot of disassembly,
but just careful work, no big deal. On the back you will see three or four
pins that stick out and make the connection into the green flexible circuit
board on the main cluster assembly. Resolder these pins' solder joints...."

I did this, and it fixed the problem.

I noticed that these connections were used to connect most/all of the guages
in the instrument cluster, and so the  fix would be applicable to tach,
temp, etc.

I was surpised at the cold solder appearance of these connections and ALL
WERE BROKEN!

BTW it was not very difficult, just take care with dissasembly/reassembly,
especially when removing the gauge at the pins where they are connected.

Use a solder iron and wick to remove the old crusty solder and resolder with
proper rosin core and flux as necessary - good as new.

Ben Swann

also..Alan chimed in..
The speedometer is the worst culprit since it is the heaviest unit, and
tends to put the most stress on the pins due to sustained vibration from the
vehicle.

Many of the relays hidden under the steering wheel and instrument clustercan
be repaired the same way. The "usual suspects" are the solder joints holding
the heaviest components onto the tiny circuit boards. Good engineering
design practices entail fastening such components mechanically rather than
using solder joints to provide this function in addition to the electrical
continuity.

The WOT/idle switch can usually be repaired too in the newer 200q20v if you
know the solder joints that go bad.

..and relating to your experience Dave, Nov. 1, 2001..
If I recall this advice was heeded with success:
[-----Original Message-----
From: Martin Pot [mailto:Paulnet at ipa.net]
Sent: Wednesday, October 27, 1999 5:10 PM
To: Swann, Benjamin R. (BSWANN)
Cc: quattro at audifans.com
Subject: Re: '86 5KCSTQ speedo intermittent? The FIX. Follow up.

Thanks, for the advice! I took the speedo out, inspected the pins, and they
really don't look very bad. There are 4of them. Should I go ahead and
resolder them anyway, or are there any other likely places that I should
check, since I have it disasembled? I did see somewhat of a hairline on one
of the pins, but am not really be able to wiggle the pin, and see it move. I
have to take it to somebody who is skilled at soldering, since I am not. I
am trying to get it back together tonight so the Q can be on the road again
tomorrow. It really did come apart without much trouble. Appreciate your
responses, Martin in NW Arkansas, nice Q country here.

<reply follows>

Martin,

Somewhere you have a loose connection, hence the intermittant operation -
those pins are the likely fatigue and failure point.  The ones on mine were
of the appearance of cold solder joints. It would not hurt for you to remove
old solder with wick(important!) and touch up with new solder.  Should not
take more than a half hour once you have it apart.  Probably under 2 hours
to remove the cluster, take apart, solder, etc. and put cluster back in.

If you need to take to someone, you can put the steering wheel on and drive
for a day without the cluster.

I can't see someone charging more than $15 to clean up where the pins solder
to the board - if you were here I'd do it for free(beer accepted).]

Salud!

Ben Swann

Now if I can only find time to work on my own practical toyz:
 '85 4KSQ - Project GTQ - someday the reworked 2.3lNG engine will be moved
from the garage floor to the engine bay - in the mean time, I am willing to
sell it for a price somewhat less than the additive value of my work/time
and parts..reference links from:
http://www.homestead.com/Ben_Swann/myaudi.html

 '87 5KCSQT Wagon - Pearl - ECU with combined QLCC chip and variable
resistor mod + 2 Bar Spring & schrapnel knob(been turned down somewhat)-
awaiting the next slew of mods to add more fuel to overcome CIS limitations
at around 2 Bar.

 '87 5KCSQT Wagon - Charcoal - still need struts and cv boot repar(PITA).