Car Alarms: Factory Security on 2000 Nissan Xterra, nissan xterra, alarmtek

Question
Hello all--

I am Stumped with this one! After changing the battery on my 2000 Xterra, the factory installed alarm system will not shut off unless the battery is disconnected--and the engine will not even "click" to turn over. I found the relay for the horn alarm and security flashers and pulled out the horn relay (so I could hear myself think) but no good. Still nothing from the engine. Any ideas?

Answer
I need to determine whether it's a factory alarm
issue or, if it's an aftermarket system you are
dealing with.

Is it: Headlights flashing, car horn honking
and a worded SECURITY or, ANTI-THEFT" light
in the dash flashing?
(doubtfull since none of the notes show this
car as having a factory alarm system)=FACTORY

Or,

is it: flashing parking lights,
an LED in the dash area, and a siren
going off?= AFTER MARKET

Let me know more on this to better
advise you on a course of action
to take.

Best Regards,

Robert Martin
CEO/ALARMTEK
CARALARMMAN.com