I had the same problem.   Was quoted about $200 parts & labor to get
it fixed.

Here's what to do to diagnose it (on an 85):
1. Remove the two screws that hold the plastic cover on the top &
bottom of steering column
2. Remove the horn pad assembly.  NOTE : there are two ways to do
this.  You don't want to remove the horn pad itself (which is held in
with 4 fragile plastic tabs with springs) but rather the larger
assembly, which is held in with 3 more sturdy plastic tabs.
2. Remove the steering wheel (24mm socket, i think).   Make sure you
remember the orientation.
3. Look at the bottom of the steering wheel -- you will see the ring
and the contact tab/brush.

On my van, the contact tab/brush was worn.  I was able to find all
these pieces at a local u-pick parts yard, so I just replaced them
all for about $25:
   Steering Wheel
   Switch unit (turn signal, wiper...)

Here are some pictures which may help:
   http://www.gowesty.com/horn_ring.htm

On Dec 15, 2005, at 5:51 AM, Greenamyer, William L wrote:

> Seems that my horn stopped working.  It is not the horn or the
> contacts
> in the top of the stearing wheel.  It appears to be a connection in
> the
> stearing column.  Have others had this problem before and what is the
> best fix?  I believe that some ring was replaced in the column before
> and I almost never use the horn so probably there is some oxidation
> built up somewhere.
>
> William