I had the same problem with my 2000 xterra and it turned out to be low battery voltage. Check your battery this is most likely your culprit.
Mudlvr
Unlock passenger side
taking out he fuse disables the whole system..your alarm will no longer work
either your battiery is dead or your starter is going out, probably the battiery though
You have a certified shop do a system performance test, unless you know how to perform such a test yourself with a manifold gauge set.
The jack is under the rear seat. Lift the seats as if you were going to lay them flat & there is a velcro panel in the center section of carpet that conceals the jack.
Not knowing what kind of alarm you are talking about it's hard to say, but if it's a smoke alarm then you should check the batteries, and the wiring. If it's a home security system I would call the person that installed it, and get them to come out and check it.
I have a 2001 Xterra that was experiencing a similar issue. The dealer told me that the remote keyless entry transmitters could act trigger the alarm when the its battery gets low. The transmitter comes apart fairly easily. On mine, there is a notch in the side where I use a quarter to pry the pieces apart. Try taking the battery completely out of each of your transmitters. If the alarm doesn't go off in the time frame that your alarm would normally go off then you know that's it. If it doesn't work at least your not out any money.
That will mess up your speedometer and odometer. It will look like you are going faster than you are (not a real problem) and your miles will add up faster (a problem when you want to re-sell).
my alarm keeps going of and wont start.
by turning the knob behind the gear shift below the radio from 2wd to 4wd 0r 4wd low. if you are going to 4wd low stop and put vehicle in neutral first.
1. Check and make sure that you have both power and ground going to the blower first. 2. Check the fuse. 3. Check the resister. 4. Check the controller head...................
You may ned to adjust the sensitivity of the motion detector. The wind is probably blowing, or a cat is walking across the car and causing the alarm to activate. my camaro was doing the same thing and i found a bad ground. check and clean all cassis grounds