ok...
well from what i've learned about alot of these systems they got away from feeding positive signals and started doing thier switching using negative feeds from the control cards, be it either the logic such as ev100 type or in these new AC systems they use a truck manager card to control alot of things such as this.
So yeah you will most likly need a diagram , schematic, something to show you the circuits.
I presume there is not a diagram inside the control panel cover?
some units have it stuck on the backside of the door or somehere like that.
since your asking for one i'll assume there isnt one :o)

dumb question but you checked all the control fuses right?