Replaced the sounder, checked the fuse (hazards still work, so can't be blown), had the airbag out and replaced that thinking it might make a difference.

It stopped working when the steering lock fell on it, it was sounding for quite a while (30seconds+) I lift the lock off and the horn stopped. Come to press the horn later in the day when approaching tight narrow bend and it wouldn't work. The fuse blew. Replaced fuse, pushed horn, no sound still. Changed the sounder at this point, no luck. Got airbag for a fiver last night, had a look under the air bag. All connections seem ok, apart from one of the switches is looks slightly melted, but not enough to stop contact/functioning correctly.

Is there a rely for the horn?
How do you change the switches under the airbag? Prise them out?
Where else to start looking?