I've looked high and low, other than killing the horn outright, is there any way to keep the car from honking when I lock/unlock the car? My 03 GT manual doesn't seem to show a method for accomplishing this.
I wouldn't think so as I've been around it quite a bit and haven't seen anything like that. There is no additional wiring to the battery or other obvious signs of an aftermarket system. I bought it in April with 44K miles and it's done it the whole time. The dealer didn't say anything about it and the key fob is factory. Of course, I knew more about the car than he did and this is my first Mustang.
When the car is unlocked and I lock it with the fob, lights flash and honks once. Unlocking with the fob, lights flash and honks twice.
Same here. Mine only honks when you press the lock button twice in succession. One honk for all OK, Two honks for something wrong. If there is no after-market system installed, perhaps there is an issue with one of your door position sensors?? Just my .02
Yeah my car is the same as everyone elses. Was there an active alarm offred on '03 gt's? If so this may be the case. As was mention on my car you press the lock button once to lock the doors. If its pressed a second time within a few seconds it will honk once if the doors are latched and it will honk twice if on door is not latched. Also our cars dont make any noise when unlocking (other then the sound of the lock mechanism moving).
Mine originally only honked on the double push of the lock button. I have since installed air horns (cheezy maybe, but they're OEM Ferrari horns I got from work) and it no longer does it. It appears that the short zap of voltage that the alarm sends the horns isn't long enough for the compressor to build up enough pressure to honk the horns. On a slightly funny note, when it's REALLY hot out the air inside the hoses going to the horns builds up a little pressure and when I double push the lock button I can hear a faint whimper coming from them (it doesn't take much to amuse me)...