The following is from Gene Heydt.
If having low beam headlamps on in fog with your "for lights" is a problem,
try this.
Buy a dpdt 12-volt dc relay from radio shack ($7.00) with 15 amp dc
contacts.
Jumper the "normally closed" contacts in parallel. Now it's a spdt
relay
with 30 amp dc contacts.
Remove the left end dashboard closure cover. It is just snapped in
place.
Remove the two screws exposed and three screws across the bottom of
left half of the lower dashboard facia.
The headlamp/foglight switch is mounted to the facia. Pull the facia
toward
the rear of the car. It too just snaps into place and with a little
tugging will
come free. Don't pull away too far as the right end of the left lower
facia
is still anchored by one screw at about mid-dash line.
The headlamp/foglight switch wires will allow 4-6" of clearance.
Cut the yel/blu (#7) wire coming out of the plug at the back of the
switch
about 1-1/2" clear of the plug.
Install the relay's "nc" contacts in this cut.
Tap the (#17) wire of the headlamp/foglight plug to the relay coil
and ground
the other relay coil terminal to the dashboard frame.
Tape the relay securely to the wire harness.
Re-install facia and end panel.
Drl's will work normally. High beam will work normally.
Low beam will work normally until you pull on the fog lights when the
power
to the fog lights energizes the relay coil and turns out the low beam!
Viola! No more low beam glare in the fog.
You can use the fog lights as driving lights with sidemarker and running
lights on during natural lighting conditions that require "being
seen" rather than being able to see. And in fog, no low beams means no
white wall in front of
your bumper.