Toyota Repair: Horn not sounding, steering wheel, loose wire

Question
Hi,  I have a 1988 4x4 SR5 22RE EFI 5 spd 192K miles.  After repairing a loose wire on a knock sensor and replacing the wiper washer pump the horn stopped working.  There is power all the way up the steering wheel, fuse is good and the horn sounds by itself with power applied directly to it.   It just won't sound when the steering wheel is pressed.
I need to know what I should test next.
Thank you for any assistance you can provide.

Answer
The horn circuit is completed by a ground connection under the steering wheel, this usually a contact ring on the bottom of the steering wheel and a spring loaded contact pin check to make sure these are making contact, the problem is up at the steering wheel.