Matrix 3 install problem

I installed a Martix3 on my 2003 ford cobra. The problem is that the car has a battery saver function that sends somekind of signal to shut off the dome light if any doors are left open for over 30 min, the problem is that the "battery saver" function triggers the alarm every 30 minutes even if the doors are shut.

Any suggestions?

Should I be using a diode? If so which one?

Thanks

Does your alarm have (+) or (-) trigger inputs?

The alarm has negative trigger inputs. I tried to contact DEI, but they said they can only help dealers. I have the wiring diagram that I got from a dealer it says to diode isolate each door wire, but it says to refer to fax document #1076 for wiring info. So basically I think I need to use a diode, but I have no idea which ones.

Thanks