how to wire schosche fdsr for factory sub

I am installing a new head unit into my 2006 Ford Explorer with factory subwoofer. I purchased the Schosche FDSR 05-up Select Ford CAN Bus Stereo Replacement Interface. This harness says it can retain the factory subwoofer. My question is how does it do that. Do I need to only plug the subwoofer RCA's coming from the FDSR harness (PURPLE / green) into the subwoofer out location on the new head unit for the factory sub to work....or do I need to connect any other amp wires. A tech with Scosche was telling me to attach the amp turn on wire (blue/wht) from the FDSR harness with the amp turn on wire (blue/wht) from the Pioneer head units harness. This didn't make sense to me. Aren't those wires for powering aftermarket amplifiers? Vehicle: 2006 Ford Explorer with factory sub/amplifier Head Unit: Pioneer AVH-P4300DVD Wire Harness/Interface: Scosche FDSR (same as PAC Audio C2R-FRD1) Link to FDSR instructions: http://www.scosche.com/ecom/download/FDSR.pdf( - _ - )

OEM amplifiers need power too.  Do as he says.

Thanks for the conformation...and for not making fun of me..hehe. You both are correct...and I shall listen. I was severely over thinking this. I got it in my head, for some reason, that the OEM amplifier was being powered by another source...when in fact he FDSR converts the 12 volt amp turn on from the Pioneer to a 5 volt regulated turn on and sends it out through the RCA's to the amp/sub...or at least that is the conclusion I have come to in my nights research.( - _ - )