triggering an alarm by cutting one wire

I need some help with this. I am installing an alarm in a 2005 kenworth truck with a sleeper. It has a refer box on the back with a negative trigger switch on the duoble doors, what i need to do is if anyone was to cut that wire which runs under the truck the alarm will trigger instantly. is there a way to wire a relay or something that will do this. Thanks....

hi,

you'll need to set up the switch at the door to open its contacts when the door(s) are opened.  wire a resistor (4.7K ohms or so) with one side to 12 volts battery, the other to your wire coming from the box you'd like to protect.  connect this wire also to the positive trigger door switch input of the alarm module.  when the doors are closed and wire not cut, the ground on them will keep the postive trigger low.  once the wire is cut or door opened, the resistor inline will apply a positive voltage to the door trigger input, setting off the alarm....DEI used to have a closed loop trigger module, not sure if they still make them however.

hope this helps

mark

hi...DEI 502T Closed Loop Trigger Module

m

When the switch is in the closed position the relay will latch until the door is opened.

This will trigger the alarm if it is still set.

If someone cuts the wire on either side of the switch the relay will drop out and trigger the alarm.

If the truck is a 24 volt system just use a 24vdc Relay.

Pins 30 and 87 follow the switch action and you would put those wires in place of the existing switch wires to the alarm.

Keep it simple!