what alarm system are you using? i know with some of the vipers there's different beeps for different modes and you can use it to tell what setting or if there's something wrong with it. if it's a dei alarm than it should be in the installation manual. but before you try that see how the ground is on the siren it could be kinda flakey so make sure it's actually a wire that is grounded inside the car and not to something in the engine bay. the rust will mess with it.