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127, New Road, Bromham, Chippenham, Wiltshire, SN15 2JA

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The alarm system consists of the following components :


Do not connect the alarm to the 12 Volt battery until all other connections have been made. The alarm should be connected directly to the battery (so that the alarm will work when the battery isolator switch is in the OFF position) Always use a 2 Ampere in line fuse fitted close to the battery.

It's well worth spending a few minutes deciding where to fit the alarm system’s components. The wiring diagram shows how the system is connected.

Control box

Once its location has been decided screw the black control box in place.

Screw the terminal block in place so that the 12-way flying lead can be connected neatly between it and the socket on the control box.


Remove the mounting bracket fixing screws, then screw the mounting bracket in the desired position. Re-fit the siren body into its mounting bracket and re-fit the fixing screws; ensure these are reasonably tight. Use the 2-way terminal block to connect the siren wires to the wires going to the control box and fix the terminal block in place.

PIR Head

This should be mounted a couple of feet off the deck "looking across" the deck. Avoid mounting the PIR head where it is directly facing the sky or where it will get wet. Remove the front half of the case by undoing the single screw near the top then carefully lowering it. The PIR head should be mounted using the screws supplied.

Connect the three wires from the control box to the PIR as shown on the wiring diagram. Refit the front half of the case and fix it in place with the single fixing screw. FOR FURTHER INFORMATION REFER TO THE SEPARATE SHEET SUPPLIED WITH THE PIR.

Door Switches

These should be fitted to doors or lockers that require protection. The switch is fitted to the frame and the magnet to the door. It is recommended that they are fitted as high as practical and on the hinge side of the door or locker. The switches are connected in series as shown in the wiring diagram.


Connect in parallel with the siren, observe correct polarity


Connect as shown in the wiring diagram using spade connectors. Fix to a suitable surface.


Please refer to the wiring diagram.

Connect the door switches to the control box using twin flat loudspeaker cable; polarity is not important.

Connect the siren / strobe to the control box using twin flat loudspeaker cable and the 2-way terminal blocks. Observe correct polarity: RED wires to SIREN+ and BLACK wires to SIREN–.

Connect the PIR head to the control box using 3 core cable as shown in the wiring diagram.

Find a convenient point to connect the red wire (terminal 2) to the battery isolator switch. Fit a 2 Ampere in line fuse close to the battery isolator switch.

Finally, connect the 12 Volt supply from the battery to the control box. Do not use twin flat speaker cable as it is rather thin for this application. A 0.75mm or 1.0mm cable (24/0.2) or similar is recommended. Fit a 2 Ampere in line fuse close to the battery.

The alarm installation is now complete and ready for testing. Ensure that the key switch is in the anti-clockwise (OFF) position, then re-connect the 12 Volt battery to test the alarm.


The button on the key fob, marked LIGHT can be used to switch the deck light if desired. The wiring diagram shows how this should be connected.

On some boats it is easier to use a relay; contact Keen Electronics for a relay and connection details.


Keen Electronics Boat Alarm Wiring Diagram.


Turn the key switch clockwise, the siren should "cheep" once indicating power has been applied. Press the ALARM button on the key fob to switch the alarm on; the siren should "cheep" twice indicating that the system is armed. Press the ALARM button a second time to disarm the alarm system; the siren should "cheep" once. When the alarm is triggered the siren should sound for 2 minutes, unless switched off with the key fob. IMPORTANT NOTE - THE FOB BUTTONS NEED TO BE PRESSED FOR A COUPLE OF SECONDS.

Arm the system and check that entering the deck area will trigger the alarm instantly (no entry delay time); the siren will sound for 2 minutes.

If necessary adjust the position of the PIR for reliable triggering.

Arm the system again and check that opening any alarmed door or locker will trigger the alarm instantly causing the siren to sound for 2 minutes. (Note all other doors must be closed)

Arm the alarm again and check that switching the battery isolator switch ON will trigger the alarm

Once the PP3 battery has been trickle charged from the 12 Volt battery and the alarm is armed, disconnection of the 12V battery will trigger the alarm.


When power is first applied the switch in the control box will be ON, so the light can be controlled by its own switch as usual. If the LIGHT button on the key fob is pressed the light will be switched OFF. Pressing the button again will switch the light back ON.