My 98 GT alarm goes off 15 seconds after I set it, It is a factory installed. It's been that way for about a year I tried it again today and same thing. Is there something I can do to reset the alarm?

 

alarms are touchy little things and there could be a couple of things causing this. How old it your battery? When the battery starts to go bad(or the connections corrode) this can cause the alarm to trip. Check the key off voltage of the battery as well as the connections to it, and the factory ground(right next to the batt with a green bolt). Try to wiggle the connectors and if there is ANY give on them then clean and tighten them.

ford contracts alot of its alarm sales to people around the dealerships so that they can add them if they want to or not. These installs are also considered "factory" but may be thrown in by billy bob who just wants to get in and out of the car as fast as possible. When they do this they often use a connectory called a T-tapp that is usually good for about a decade, which is how old your car is. Poke your head up under the dash and see if you can see any wiring that does not look like it belongs. If there is nothing there then you may need to remove the drivers kick as most of the connections are back there.

 

Ok thanks, where is the alarm likely mounted? Is there a reset button?

 

there is no reset, and after installing for almost 15 yrs I have no idea where the factory alarm is. I never messed with them.

Again, start at your battery and its connections.