Car Alarms: 2000 xterra, car horn, odd behavior

Question
QUESTION: the factory alarm, when set will start honking(triggered) for no reason  it turns off fine by sending the unlock signl from remote, and rearm when sending signal from remote.  the alarm get triggered for no apparent reason


ANSWER: Does this alarm have a siren or
does it honk the car horn and flash the
headlights?

Factory and after market alarms differ
in how they operate, but essentially detect
an open circuit.

It would help me to know more, so I can assist.

ALARMTEK

---------- FOLLOW-UP ----------

QUESTION: the hornhonks and lights flash
also i locked the doors with the key (did not set the alarm) and it still triggered ( it takes hours sometimes before it triggers

Answer
Ok, if this is indeed the factory system, it is detecting a spike in the power system. That's the ONLY way they can be triggered.
Usually it is traced to a badly performing battery or charging
system, but it is dependent on the battery in all cases.

Replace it and see if that solves all the odd behavior.

Good luck with it.

ALARMTEK