There's no "coil 3" in the way you might be thinking on a 2004 Lincoln LS engine. The 2004 Lincoln LS uses a
coil-on-plug (COP) ignition system. This means each spark plug has its own individual ignition coil directly mounted on top of it. There isn't a separate numbered coil pack.
To find a specific coil, you'd need to identify the cylinder number you're interested in (1-8) and locate that cylinder's spark plug. The coil will be directly on top. A diagram in a repair manual or online will show the cylinder and plug locations.