If you're feeling any air, it's not your fan. If your car is newer and never been recharged, I would try that. Hopefully, it's not your compressor because replacing those things is expensive!
2011 Mustang 3.7L, 6A, MCA Pkg, Ingot Silver w/ Stone
Perf Mods: FRPP 3.73 Gears, 87 Octane Performance Tune from BAMA, Airaid CAI, Magnaflow Comp Axle-backs
Ext Mods: Lower chrome billet grille, Tint
Upcoming Mods: Lowering springs