Aux Fuel Wiring Diagram for 2015-2017 Mustang EcoBoost

The 4 YELLOW wires with black stripes will tap into the coil pack outputs at pins 42,43, 57, and 72 on the c1551E plug (the topmost plug on the ECU). It doesn’t matter which of the YELLOW wires go to which output, only that they each go to their own output

The GREEN wire will tap into pin 33 on the c1551E plug. 

The RED wire will need 12 V+ and the black wire will need to be grounded. There are many ways to do this, including using a make-a-circuit to tap into the fuse box.