A bit confusing as there is two diagrams on that page.
I am not sure what to make of this one, since there are wires for burglary power, power switch, and signal theft.
I would think power switch would be the one to connect to battery, through a switch, if it was red. looks like another color to me though.
I'd start with just trying the two power wires, see if it does power up. If not, start asking the vendor WTH?
Use a stout plug for the switch if you get it powered up. Switches on the main battery wires just fry, unless they are expensive, heavy contactors.