Where is the cylinder 5 coil pack on a 5.4 v8 2005 f150?

On a 2005 Ford F-150 5.4L V8, the coil packs are not numbered sequentially by cylinder. They are arranged in pairs, and the location is generally on top of the spark plugs. There isn't a "cylinder 5 coil pack". Instead, cylinder 5 will be fired by one of the coil packs.

To find which coil pack fires cylinder 5, you'll need a wiring diagram or a repair manual specific to your 2005 F-150 5.4L. These diagrams show the coil pack arrangement and which cylinder each coil pack is responsible for. Looking at the engine from above, you'll see the coil packs, and the diagram will tell you which is the correct one for cylinder 5.