check the "horn contact" which is directly under the cap of the middle of the steering wheel, it just prys off (carefully!). See that it makes contact with the other parts under it. I have dissassembled mine before its not that hard. Buy a steering wheel puller from Supacheap, I dont think they cost much and is always handy for use if you need it later. Basically it pulls the nut away from the column. then its easy to look and check all the contacts down further in the column. Just remember the order it came off! Like the others said also, see if a electrician can pin point the problem to see if the problem could be else where. Check the actual horn, a wire may not be contacting?
1969-74 Horn Contact Kit With Tilt-Telescopic Column
Fixes 90% Of Horn/Button Failures
Repair Parts And Replacement Parts
Most horn failures occur at the button due to broken horn contact buttons and contact brush insulators. This kit contains these parts plus the horn contact, spacer and screws.
Item# 38134
In Stock
$39.99 kit
Hopefully this will fix your horny problem!;41