Im having some issues with my factory alarm system. It all started about a year ago. The horn switch, the pad in front of the airbag, became faulty causing the horn to sound constantly. Instead of buying a new airbag, since ford doesn't sell the switch separately, I got a push button switch. After I installed the switch the horn will not sound when the alarm goes off. It will chirp when a door is open, if it attempts to arm itself also when the panic button is pressed (but only intermittently). I tried diagnosing it today, with my factory service manual, and there is continuity from the relay to the RAP module. The horn circuit is fine, It will sound if I push the switch. The only thing I haven't checked is the ground, because everything else about the alarm is fine but the horn. I will look into it tomorrow though. On a side note the cigar socket has never worked in this car, It always blows the fuse or burns out the socket. I found in the service manual that the RAP module and cigar lighter SHARE THE SAME GROUND!!! 8O If that ground is the problem for both why would just the horn fail and not the whole system? And why would it happen now and not 10 years ago when the cigar lighter failed? Any thoughts or opinons would be great.