pre-warn negative trigger input

i have a blue/white wire that is on my alarm it goes to the pre-warn trigger input (-) but it dont go to the dual shock sensor because it has a plug that goes to it were do i hook this wire up to?

In some lower line of alarm systems, the maker provides a dual stage shock sensor with only (1) one master adjustment pot / dial to increase and decrease the sensitvity. If this is the case, then the shock / motion sensors pot-dial adjusts both zones at once, and also sends out the prewarn chirp to the alarm brain, without the use of the independant wire you have in your hand now. Assuming you want to upgrade the unit, you can utilize this wire, where the sensor has the prewarn output wire. Regards EVIL Teken...

the sensor has 2 adjustments on it for sentisitivity so do i not need to use this wire or what?

The way you discribe the sensor, it does not require the other lead. Does it pre-warn now, without it? If so, then the sensors internal circuitry is sending out the pre-warn chirps either to the alarm CPU, or directly to the siren itself.