Where is the alarm module housed on a 2004 ford explorer?

Location of the alarm system on a 2004 ford explorer

Factory?
The Passive Anti-theft Tranceiver is mounted inside the steering column, on the bottom.
Non-factory?
Could be located either under the dash on the driver's or passenger's side behind the close-out panel. It may be located elsewhere but these are the most common places I've seen them located.