Pinpoint Test G: The Audio Control Module (ACM) Illumination Is Inoperative: Notes
WARNING: This page is about a different car, the 2008 Ford Pickup, 2008 Ford F550 Super Duty, 2008 Ford F450 Super Duty, and 2008 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Refer to SYSTEM WIRING DIAGRAMS - F250 SUPER DUTY , Cluster and Panel Illumination for schematic and connector information.