Found this for the 2007 F150 on another forum:
Originally Posted by
F150 Manual, pg. 137
Enabling/Disabling the perimeter lighting feature
Your vehicle comes with the perimeter lighting feature enabled. All vehicle doors must be closed before beginning the procedure. You must complete Steps 1-5 withing 30 seconds, or the procedure will have to be repeated. If the procedure needs to be repeated, you must wait a minimum of 30 seconds to begin again.
1. Turn the ignition to the ON position, then press the unlock control three times.
2. Turn the ignition to the OFF/LOCK position, then press the unlock control three times.
3. Turn the ignition to the ON position; the horn will chirp to indicate the driver configuration mode has been activated.
4. Within five seconds, press the unlock control two times.
Note: One horn chirp should be heard, indicating the system has been disabled. Conversely, a horn chirp followed by a honk will indicate the system is enabled. Pressing the power door unlock control two times again will turn the feature ON if it was previously OFF, or OFF if it was previously ON. Every two consecutive presses of the unlock control after successfully entering the configuration mode will change the enable/disable condition of the feature.
5. Turn the ignition to the OFF/LOCK position to exit programming.
Note: After exiting the driver configuration mode, the horn will chirp once to indicate a feature has been activated/deactivated.
@Fred