Horn problems...

Hi All, I have a 1996 P38 4.6 HSE. Recently I have had a problem with the horn sounding at random moments. Sometimes it can go for days without a problem, then it will sound for no reason as I drive along. It doesn't seem to be related to any other event - such as going over a bump or pressing on the steering wheel! If anyone has any ideas where to start looking into this one I would be grateful. The MOT is just weeks away!

The Horn is controlled by a tiny relay in the engine fuse box...maybe the contact return spring has failed allowing the contacts to flop about activiating the horn...

Pull the relay and shake it, if it rattles, it could be duff, if not, apply 12V across the appropriate legs and see if you can hear the relay clicking....failing that, wiggle the airbag module on the steering wheel, the horn button is underneath it and it has a return spring, if the airbag module is loose or rattly, this couls indicate the return springs are weak causing intermittent horn operation.....

Download RAVE and check the wiring diagram to spot the earth points as a spurious earth leak could cause it too....

Rotary coupler behind the steering wheel. It's happened to me on other cars.

Hi my 99 p38 dse has the same problem,horn sounds intermitentley then nothing for days changed coupler twice now and still the same so am thinking of takeing wheel off and changeing over horn parts to see if that helps.Had it looked at twice but still the same probs.