my car alarm is a cobra alarm model is 7777
the problem ive got is that my alarm was working but all of a sudden its not working ive got to use my key to open and lock the door the alarm sytem does not go off when i sit in the car it only goes off when i start the engine or open up the boot ive tried resetting it but still with out any luck.the previous owner does not have the manual or any pass codes so im stuck on what to do ive tried looking for the box under the dash but i can not find it or im looking in the wrong place.Ive never used a cobra alarm so im really stuck on what to do please please help need all the advice that you can give me