There is a thread related to 147 squibs already however my problem is slightly different.. My horn stopped functioning a few weeks back, it would come on intermittently. My airbag light was also on which was caused by me installing leather seats (so the light is probably unrelated).
I had an alfa/fiat mechanic look at it and he claimed one of the sensors was gone.He didn't seem certain though. Then I brought it to a garage and they let me look as they dismantled the airbag (bit reluctant to bring me out the back but I said I'm 'curious'
He ran a volt check on all the sensors and the horn did come on and worked a lot, but every now and then, maybe 1 in 5, it would only work intermittently. He seemed a bit frustrated and said, 'the sensors are fine, you need a new squib, not the cheapest of parts, better off getting new steering wheel'. The horn did work for 24 hours after this, it was great, I was beeping at everything, people, dogs, birds, even combining the 'alfa wave' with a friendly beep!
Then it went again, I don't know what to do, who to believe, what to buy? Any light on the issue much appreciated,