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Re: bad fuel pump relay/socket

from mallick@ausable.crd.ge.com (John Mallick)

>If you can, take the cover off of the relay and look at the contacts
>and circuit board.  My '84 4000sq died last year, and I finally traced
>the problem to a cracked solder joint on the little circuit board
>inside of the relay box 


My power windows/sunroof became occasionally intermittant, and I 
traced it to the "relay", ( you know the yellow one just above 
the cruise control ). Many of the boxes that Audi calls relays 
are usually small circuit boards containing a relay and other 
electronic components. Now here comes the problem. The real
relay weighs quite a bit more than resistors and capacitors,
and when the assembly is subjected to the SERIOUS vibration
that Audis get ( no soft sprung cruiser ) the solder joints
subject to the most stress are the ones holding the relay
(the real relay ) onto the circuit card.

( Personal comment: BAD DESIGN, they should not use through-hole
solder pins as a means to mechanically mount heavy components )

Most will not give trouble, but every now and then the "relay"
assembly will fail. If one does, pry it open and resolder the
legs of the relay and any other heavy component you see. It may
not fix the problem, but it is worth a try.

(Another possible solder joint that is more likely to fail
would be the ones carrying heay currents. The fuel pump
current carrying contacts ( not the coil contacts ) would be
an example, or the place where the diagnostic fuse goes
into the top.)

Alan Cordeiro
'86 5kTQ