The below schematic should be used to wire the FAST remote IAC to the Holley main harness. Removal of the flat Holley connector will be required to splice in the supplied square connector. Use the below schematic for proper installation.
Holley harness purple/yellow to connector terminal A
Holley harness purple/blue to connector terminal B
Holley harness purple/black to connector terminal C
Holley harness purple/white to connector terminal D
The pin layout is provided in case it is needed. The barrels of the supplied connector points towards you with the connector tab on top and the wires out the rear for correct terminal orientation.