Hi. The car (2003 XKR) has started randomly and briefly sounding the horn, when driving. It doesn't seem to have any pattern.....not always over bumps, when turning the steering wheel etc......just a very short 'bip' or sometimes two.
Any ideas where to start the hunt for the culprit ?
Cheers.
Rob

 

I think I'd start with the relay as it's the easiest bit to get to (engine compartment fuse box). First test - remove the relay and drive the car, does the bipping stop? You could try a replacement relay, after that it's the steering wheel cassette and the horn buttons.

 

With the relay removed, surely nothing would work, as the signal from the horn button would not be received and relayed to the horns themselves?

 

Development......seems to happen primarily when turning wheel anti-clockwise, so am assuming it's something on the steering wheel boss ?
Can anything be checked/cleaned with wheel in place ?

 

Exactly, that is what you are checking, with the relay removed the horn stops sounding. When fault finding the quickest way to waste a lot of time is to not bother to check the easy things on the grounds "it can't be that".

Next is check the cassette, which is probably where the problem is.