Fog Lamps...the how to

[Chris Tucker <ctucker@du.edu>]

Robin,

There has recently been a lot of talk about what laws require the low 
beams to be on with the fogs.  I would try the q-list archives to get 
more information of the why at
"http://coimbra.ans.net/cgi-bin/lwgate/quattro/archives".

Following are a few responces that I received when I first ask the how 
question.  After the responces I will describe how I rewired my 90 80Q so 
the fogs work with the parking lights on.

-----------------------------------
My 89 90q has the rear fog light on the left side, with a switch for it 
in the dash next to the switch for the front fogs. That switch BTW, has 
been modified to let the fogs come on with parking lights or low beams or 
high beams......he he he

It's pretty easy, as some of you have asked for, all I did was to cut the 
power lead to the switch (which usu only shows 12v when the low beams are 
on) and replace it with 12v off of a relay triggered by the dash light 
circut. This way, no matter what the head lights are doing, the fog light 
switch always has power.

Have fun, and remember your fuses!

----------

The reason the fogs operate with the low beam is because the relay (for 
the fogs) is triggered by the low beam (it is the law!), at least that it 
the way aftermarket lights work.
 
If you want to make the fogs come on with the parking lights, you have to 
add a 12volt wire from the parking lights, the 12 volt from the parking 
lights will trigger the relay and you will be able to turn the fogs on 
with only the parking lights on. There is not much value in leaving the 
low beamconnected to your fogs but it should not hurt I hope it helps.
Avi Meron

----------

I just recently moved the power pick off for the fog relay from the low 
beam hot wire to the parking lite hot wire. Now the fogs work as long as 
the parking lites are on (including with low and high beams) My fogs are 
powered directly off the battery post (via fused 20 amp relay) in the 
engine compartment, so I am not worrired about the extra current draw 
when the high beams and the fogs are on at the same time.

mike miller

---------------------------------------------------------
And now my explanation:


I always seem to make an easy job hard.  After spending a lot of time
poking around try to find a hot wire to my 80Q's fog relay, I bought the
Bentley ELE manual to help find my way.  I originally wanted to switch 
some wires on the 
fuse box.  It seems that there needs to be two hot wires to the fog relay 
to make it work.  One from the Load Reduction circuit (which is only hot 
when the lows are on and is the power supply for the fogs) and one from 
the dimmer switch.  I did't what to mess with the Load reduction 
Circuits so I scraped that idea and found an easier way.

I used a hot wire from the parking lights to replace the hot wire
from the fog relay (it's only hot when the lows are on) on the back of
the Audi fog switches.  Then I added a relay and fuse for the fogs.
Easy, right.

My parking light hot wire is off of the headlight switch on the steering
column.  I had to top steering column cover off, so a unplugged the
connector to the head light switch.  I found the parking light wire,
GREEN/RED, pulled it out of the connector and soldered a secondary to it.
I then reinstalled the parking light wire into the connector and plugged
the connector back onto the head light switch.  This was probably a little
extreme, but I had it apart.  Any wire that is activated from the parking
lights will work.

I then pulled the stock fog light switch from the dash and found the hot
relay wire, GRAY/GREEN. I pulled the GRAY/GREEN wire and replaced it with
the hot parking light wire.  For reference, the WHITE/YELLOW wire from
the back of the fog switch, goes straight to the fogs.

A relay must be added.  With out a relay I am bypassing all fuses and all
the current is being drawn through the headlight switch, not good.  I'm
adding my relay tonight.  A relay draws power from an isolated source and
is activated from the switch.

I putting my relay on the engine side of the fire wall.  The relay
has four connections that need to be made. 1) Power will be drawn
straight from the positive terminal of the battery to the +power of the
relay.  2) The relay needs to be ground to the body. 3) WHITE/YELLOW wire
from the fog switch.  4) Wire from the relay to the fogs.  When the fog
switch is turned on, it activates the relay to draw the fog's power from
the battery.  I'm also adding a fuse between the + battery terminal and
the relay.

I'm sure there are different ways for doing
the connections but the concept should be the same.  Remember that the
wire colors are for my 90 80Q and they might be different on your S6.  I
only removed the top cover of the steering column, not the steering
wheel.  I had no desire to mess with the air bag stuff.  Be aware that
the air bag is there and can be dangerous.  I also would disconnect the 
battery when doing any electrical work.

I think that everything.  Good luck

Chris Tucker
ctucker@du.edu
http://www.du.edu/~ctucker/tucaudi.html


On Sun, 3 Nov 1996, Robin Samms wrote:

> Chris Tucker http://www.du.edu/~ctucker/tucaudi.html
> wrote:
> 
> > > 
> > See how I'm not an electrical wiz, maybe someone out there can tell me an
> 
> > easy way to "remove" this feature.  For heavy snow it would be nice for 
> > the fogs to work with the parking lights on, not the lowbeams.
> > 
> One of the few annoyances of the S6 is that the fogs don't work with just
> parking lights on.  I am used to all other German cars I have owned (BMW &
> Porsche)
> allowing fog lights on pk light only.  Is this an anomaly ? do all the
> S4/S6 cars work this way ? Or do I have one of those famous "uniquely wired
> " cars that Audi seems to put off their production lines every so often. 
> Finally, is there a fix for this  ?
> 
> Robin
> 
> -----
> Robin Samms
> Seattle, WA
> 95? S6W, 83 4KQ
>