Hi! In my '04 'vert 3.8 V6 the theft light is still on, the engine starts and the car goes with no problem. I tried with both the keys I have, also living the keys in ACC position for a while. Before after a while driving the light went off, but now stays always on either with the car stopped and closed or driving.
Any suggestion on how to do for switch off the light?
Thanks.

 

Ok, here's the deal, if I'm reading all the searches right:

1994 did not have 'Factory Alarm'. They had a dealer installable module. PATS wasn't a thing until 1996 in the Mustang. Just fyi.

The light being on usually indicates the alarm system is just unhappy about something. It can't 'see' something happening with the sensors or whatever that it wants to see. So it just turns that light on and you're supposed to go to the dealer and get it attended to.

Now, if you want to figure it out, you'll just have to keep on googling, or if you wanna go through the diagnostic process, you'll need to acquire the *real deal* 1994 Ford Mustang applicable Service Manual. Not the owner's manual. Not the Chilton or Hayes. The Ford one. Which will cost a little bit of dollars. Because only that one has the wiring and diagnostics and all that to guide you correctly.

Or you take it to a dealer and pay through the nose to have them figure it out.

Or you take it to a shop that's reputable to figure out and fix this sort of thing, and do it on Fords, and will charge you a little less from the nose than the dealer... if you're lucky and they can fix it, and not spend a gawdawful amount of diagnostic time figuring it out...

The alarm system is probably not going to work correctly if the light is on. It should only ever be slowly blinking or off, IIRC, so in this state, it's not being armed and 'protected'. If you're ok with an unguarded car, then you can just ignore the lamp/tape over it. I'd be getting it fixed, myself, but that's me.

Probably not what you wanted to hear, but that's about it. Good luck, hope it helps!

And welcome to the forums!

 

Hi houtex, thanks alot.
I made a mistyping, the car is a '04 (2004) and not a 1994, so assume she has the PATS.
Unlikely I'm in Italy, so there are not so much dealers or auto repair confident with this car. Now is here the new 2015 model, and I'll go for a ride test in short time, and hope the official Ford dealer can fix this.
What about disconnect the battery for a while and try to rset in this way?

 

Ok, well, the same stuff is in play. If the car's still starting, then it thinks your key is just fine, and that's good. So it's something else in the PATS/Securilock system that's ticked off, and you'll just need to get the car scanned or diagnosed to figure it out.

The battery reset, sure, you might can try that, but I wouldn't hold out a whole lot of hope it'd fix it, myself. These are usually hard wire faults or module faults of some sort, not logic issues in the module that can be forgotten. But it's worth a shot, sure.

 

Searching seems to be the triac that drives the theft light led, does anyone have the instrument cluster schematic?