testing alarm outputs

I have taken the four dioded leads off the green negative trigger wire. I reattached them one at a time. They all will trigger the alarm when their respective door is open; as long as no other lead is attached. As soon as I add two triggers to the mix, no reaction. It sounds like a diode situation to me. I'm sure I installed them properly as was illustrated in the 12volt.com diagram for a negative triggered system. Cathode toward the trigger. Thoughts or solutions? Thanks 

this car has positive triggers.

change all your diodes, you want the silver band on diode to be towards the alarm, or away from the door trigger wire on car.

Thanks for the reply. Do you know the procedure to test to see whether a car has neg or pos triggers? I've got 3 different install and wiring guides and they all state neg triggers. I'm not saying you are wrong, but I'd like to know how to double check them. Is it as simple as checking for voltage before the diodes? Ground when closed,12 volts when opened? Thanks