Another thought Les is the switched ground to the horns. As you likely already know this is carried on the purple/black wire to complete circuit to horns.
![[Linked Image]](https://i.ibb.co/GvTgV4Z1/i5Mk9p-Z.jpg)
The connection through to the steering wheel slip ring is via the brass slip ring contact shown above secured by small screw. This is part of a brass strip that clips to a spade connector on back of light switch module which in turn gets its connection through the main seven pin light switch connector where you will see the purple/black wire running into the loom and on to both horns. It may be worth checking integrity of these various connections therefore, especially if light switch is ever replaced as this contact can be disturbed. The actual ground connection you enquired of is the steering column itself connecting via spring retaining clips on metal body of horn push when pushed back in to steering wheel boss centre, noting there is a short lead with female spade connector to the slip ring that needs to be detached for complete horn push removal. This on my MotoLita wheel and something similar with factory padded wheel.
A quick test with steering wheel removed is to switch key to auxiliary or ignition on position and hold a short piece of wire against any chassis point whilst dabbing other end on brass slip ring pickup and seeing if horns sound.
