I have just installed a new battery in a 2004 focus and now the alarm system keeps going off what do you do? Tried diconneting and then reconnting still the system continues to go off

If you have a remote, lock then unlock the doors using the remote. That should stop the horn. If that doesn't work, use the ignition key in the driver's door lock and turn the key all the way to the left, then all the way to the right. Of course, this all has to be done with the battery connected, and the horn honking the whole time. If none of this works, look for a reset button under the driver side dash, or it may be a toggle switch. With the key in the on position. push and hold the button until you hear a beep from the alarm. On some cars, the reset button is behind the driver side kick panel.