1991 200T

[Buchholz, Steven]

> I have a 200T and would like to know what rear fog lights do?  I have a
> switch for them on the dash.  I also would like to know if there is any
> way to increase the engine thermastat temp. because in Fairbanks,AK  at
> -40 the engine needs to run warmer for the heater and such to work.

The rear fogs turn on a light that is as bright as a brake light on the left
rear of the light bar.  The light is usually set up so that it will not come
on unless the headlights and the front fog is on as well (actually I think
that turning on the rear fog on my V8 automatically turns on the front fog
too).  It is intended to make your car visible from farther away in dense
fog situations, but even though the light is only on one side, the rear fog
can be confused with a brake light ...

On your other problem ... your car may actually have a bad thermostat ...
you may want to simply try replacing it with a stock unit.  When the temp
gets cold the t-stat is supposed to decrease flow to the radiator to keep
the engine temp up.  The heater is hooked up to the engine, so that when
flow stops to the radiator the warm water in the engine continues to flow to
the heater core.  One other thing you might want to consider doing is
putting a piece of cardboard in front of part of the radiator when you know
it is going to be very cold.  You might also want to fit something behind
the grille to keep the cold air from flowing through and cooling the engine
block directly.  My old '78 Fox GTI had a moveable door in front of the
engine compartment that was supposed to be opened in warm climates and
closed in the cold.  

Even though we don't often see anywhere near -40 here, I did get to spend
time thinking about this issue when the thermostat went open on the '88
5kCSQA while driving on the freeway when the temp was below freezing.  I
wish I would have thought to simply stop and block off part of the airflow
through the radiator!  It was getting pretty chilly inside the car and it
was impossible to keep the windshield from fogging up on the inside surface
...

HTH!
Steve Buchholz
San Jose, CA (USA)