How to Hook Up a Horn to My Existing Home Alarm System

Turn the horn around. Open the battery compartment lid -- loosen the screw first, if there is one, using a Phillips jeweler's screwdriver. Insert the appropriate number and type of batteries into the battery compartment. Close the lid and tighten the screw, if there is one. If there is no battery compartment, plug the AC cord attached to the horn into a wall outlet after it has been mounted to the wall.

Mount the horn on a wall in an out-of-the-way spot so it can not be easily found. Use wood screws and a Phillips screwdriver to do this. Loosen the two screws on the bottom of the horn and wrap the end of a wire attached to the wireless transmitter around each screw. Tighten the screws. If there are no screws, insert the mini jack plug at the end of the cable attached to the wireless transmitter instead.

Turn the wireless transmitter around. Open the battery compartment lid by loosening the screw, if there is one, with a Phillips jeweler's screwdriver. Insert the appropriate number and type of batteries into the battery compartment. Close the lid and tighten the screw.

Mount the wireless transmitter next to the horn on the wall. Use wood screws and a Phillips screwdriver.

Enter the password on the alarm system's control panel keypad or "Virtual Keypad" on the LCD screen to disarm the system. Navigate to the "Configuration" menu. Check the check box to activate an external audio source If the alarm is activated. Check any other check box related to this.

Press the "Sync" or "Activation" tab or button on the side of the wireless transmitter attached to the horn. Press the similarly named button on the control panel. If there is no button on the control panel, activate the "Sync" or "Activation" button by checking a check box, pressing a button on the keypad or on the "Virtual Keypad" on the LCD screen.

Enter the password once more to rearm the system.