I had same problem on my '84 and found that fuse had blown.  Replaced
very old fuse as temporary fix until I can get new motors installed.
Until I had time to get under the dash with a bright light, I used RainX
with cleaner on the outside surface of the windshield and RainX anti-fog
on the interior.

John

On Fri, 2011-12-30 at 20:26 -0800, David White wrote:
> 200 miles to the coast in the rain. 3 days at the coast in the rain.
> 150 miles returning from the coast in the rain. Lost both the dash
> heater motor and the rear heater motor under the rear seat and the
> wiper motor instantly with a slight wisp of burning wire under the
> dash. Fuse number 10 is still good as are the two fuses under the
> steering column. Where do I start looking for the problem?  84 westie.
> I also learned that some of my fuses are black instead of the classic
> red or white. black in position 10. red and white in positions under
> the steering column. What's the amperage on black ones? My eyes are
> too tired to see what it says on the backside.