Car Alarms: car alarm will trigger 30 seconds after car is locked with the remote, ford fiesta mk4, pin switch

Question
i have a UK 1997 ford fiesta mk4 with an aftermarket alarm, every time i lock the car, it will lock, then it makes a sound, wait 20-30 seconds and the alarm will go off every time, any idea what the problem might be? cheers

Answer
May be a delay on the door trigger, dome light
circuit. Try this:

Turn off the key, open, then close the door and
wait the 30 seconds. Then press the lock button.
If I am correct, the reason yours goes off is that
it "sees" the power on the dome light wire, and
triggers. If you can do this delay, and it works,
the alarm you have will need to be adjusted to
allow for a 1 min. delay of your dome light system
before arming to allow for it, or you can simply
train yourself to wait for the interior lights to go
off prior to setting the alarm.

If however this is not the issue, then you
will need to locate the open circuit setting
off the alarm, and repair.

Could be anything from a faulty
door pin switch, to a device that draws 12 volts
with the ignition key off. But this is what
appears to be happening.

Let me know what you discover.

ALARMTEK