hi, just bought a rover 600,but i cannot get the alarm to work,the central locking works on my fob but no alarm,even when i lock the drivers door by the key,it still does not work. have fitted 2 new door lock censors due to one being faulty,think this may have been a problem to the last owner,maybe it kept going off ,where might have he disconnected it from,because i have looked,but cannot find where it might have been disconnected from? Help???