No Modification to the harness. I did this conversion on my 2010 Pony Package.
Thanks for the confirmation once again! Read a 7 page thread from a while back regarding the conversion that I believe myself and even you were apart of ealier lol.
GRABBER BLUE 2012 Mustang Coupe V6 Premium|Pony Package*
Performance: Airaid Intake, SCT SF3 Tuner, BBK Ceramic Shorty Headers, LethalPerformance O/R H-Pipe, FRPP Sport Axle-backs, JLT Oil Separator, DriveShaftShop Aluminum Driveshaft.
Suspension: Boss 302 Strut Brace, Steeda: Chrome Moly LCA's, Adj.UCA, Adj.Panhard bar, Ultra-Lite Springs, Pro-Action Shocks/Struts, Heavy-Duty Caster Camber Plates & Trunk X-Brace.
Wheels/Tires: Staggered 19" Forgestar Wheels with Nitto Invo Tires.