thieft

while replacing the speakers on the left and right of the car door, i believe i triggered the anti thieft alarm. i beleive this because,

#1: the red light that sez "theift" is blinking. :icon16:

#2: i can not turn the key.

this is a 2004 mustang coup.

what do i do?

The anti theft system doesn't prevent the key from turning, it just makes it so when you turn the key it doesn't do anything. Its also supposed to say "theft" until you start the car with the key.

Try turning the key while turning the steering wheel left and right. If it was turned off with the wheel slightly turned, the lock mechanism is being held tightly against the cylinder preventing it from turning. Its like trying to unlock a deadbolt while you're pulling the door; the friction is too much to overcome with the key.