Mirror Control Assembly Lamp Repair

[KSMITH1@mailgw.sanders.lockheed.com]

Greetings, Listers:

As an offering of thanks to the list, particularly to all 
who have helped me with radio and seat heater lamps,  I 
provide the following description of the details of 
replacing the bulbs in the mirror control assembly located 
in the driver's door console.  Although performed on a 1988 
90q, the procedure should be applicable to a range of 
models.  Those experienced with seat heater switch bulb 
repair will find the process similar.

First, remove the console assembly from the armrest.  This 
process is illustrated in the Bentley.  The steps are, 
briefly, remove the Phillips screw that holds in the lower 
plastic piece under the armrest.  Remove the lower plastic 
piece, left edge first.  Remove the two now-revealed long 
Phillips screws holding the plastic extension of the console 
assembly.  Pull the console toward the left and raise it a 
little.  Note the following:  the right hand side of the 
console is held in place by a pair of tangs that fit under 
the right hand edge of the armrest.  They are about 2 mm 
long, so that much movement is needed.  This requires 
pushing down in the center of the console while pulling 
left.  But first, use a plastic body filler squeegee, or 
similar non-marring tool, to slide up alone the console 
outside edge toward the top.  Then, performing this three 
handed maneuver with two hands, pry up on the right hand top 
edge while trying to generate the 2 mm gap needed.  If and 
when you are successful, you can pull up the whole assembly 
about an inch (25 mm) or so, taking care not to damage the 
vinyl on the door.

Disconnect the electrical connector to the mirror control 
assembly.  No other connectors need be removed if only the 
mirror control is to be repaired.  On the right hand of the 
underneath of the console assembly is a plastic tang 
overlapping a protrusion on the mirror control assembly.  
Pry the tang slightly to the right and release the 
protrusion slightly.  Using a hook of some kind, then pull 
the spring-loaded tangs on the left of the control assembly.  
The control assembly should now be free and can be removed 
through the inch or so gap between the console surface and 
the armrest.  Now you can take the control assembly to a 
work area where small parts can be kept under control.

The mirror control assembly is constructed in a manner 
similar to the seat heater switches.  That is, there is a 
plastic shell that overlaps a set of protrusions.  Removal 
is annoying but possible.  I started at the spring-loaded 
tang end and used shim stock to hold the tangs in.  The shim 
stock goes under the plastic shell.  Then I used jewelers 
screwdrivers to pry the other areas of the plastic shell to 
get them up over the protrusions.  This is harder than for 
the seat heater switches as there are 6 protrusions 
altogether plus the spring-loaded tangs.  But success comes 
to him/her who is patient.

Pull off the plastic shell with the control side down!  This 
will keep two ball bearings under control that are balanced 
on two posts.  Put another way, pull out the circuit board 
with attached connector pins by pulling up.

Once exposed, the two lamps are obvious.  They can be 
replaced with the usual radio shack grain of wheat 60 mA 12V 
bulbs.  Note that Audi will not likely obtain a NASA quality 
award for their soldering/circuit board construction.  Use a 
solder sucker on the lamp connections and keep your iron 
temperature just high enough to melt the solder cleanly 
without burning the flux.  Check the other joints for cold 
solder connections.  Check that the circuit trace did not 
move and cause a short.  Check that the solder did not 
overrun the narrow circuit trace gaps and cause a short.  
Clean off the new flux with denatured alcohol and a brush.

If necessary, the control assembly contacts can be cleaned, 
including those under the rubber pad.  Depending on the 
selection of cleaning solvent, you may or may not improve 
things. 

Reassemble in reverse order, making sure the ball bearings 
are in their proper location.  Once the plastic shell is 
snapped into the protrusions, you don't want to go in there 
again.  Return to the vehicle and test the control assembly 
by reconnecting it outside the console.  The connector 
should reach.  The ignition key has to be on to run the 
mirrors.  Shield the assembly from ambient light and check 
that the new lamps work.  (Turn on the headlight switch.)  
If everything checks out, the control assembly can be 
reinstalled in the console, reconnected, and the console 
returned to its normal location.  Be sure all other 
electrical connectors are in place.  (Turn off the key and 
the headlights.)

I found reinstalling the console to be tricky, as there was 
always some part that wanted to obstruct the reassembly.  
Some weaseling was ultimately successful in getting it back 
into position.  Push to the right to engage the two small 
tangs, reinstall the two long screws, the lower plastic 
piece, and the exposed Phillips screw. 


***                 ...Kirby    (Kirby A. Smith)                 ***
***              ksmith1@mailgw.sanders.lockheed.com             ***
***              [=]   kirby.a.smith@lmco.com                    ***
***  Opinions expressed herein are entirely those of the author. ***