Horn problem - stumped

["James Pickard" <geowiz.sgy@cox.net>]

This one has me stumped.  My HIGH horn doesn't work.  It works fine on a
bench test when hooked up directly to a 12-volt car battery.  But it doesn't
work in the car.  The LOW horn works fine.  I've tried swapping sides, but
it makes no difference - the LOW horn works on both sides, while the HIGH
horn never works in the car.  The HIGH horn just goes THUNK.  Suggestions?

Jim Pickard
B9473298
Lafayette, LA