It is almost impossible to diagnose this without the Ford NGS scan tool. You need to check for codes and the repair procedure calls for looking at data through the scan tool. The main problems though that Ford had problems with is the brake pressure switch (this is why there is a recall on the switch wiring on some of their vehicles, yours is not in this recall). This switch is set up to be a back up in case the brake pedal switch fails. The brake pressure switch is located on the bottom of the master cylinder. If memory serves me correct the computer needs to see the switch closed, meaning the power needs to flow through the switch and back to the computer. If this switch fails it will cause an open telling the computer that you have applied a lot of pressure to the brake pedal. You can unhook this switch and put a paperclip between the two terminals and drive it to see if the cruise works be careful not to let the paper clip touch any metal or you will blow a fuse. If it works replace the switch. If it doesn't work try pulling the paperclip out and trying it with the connector just unhooked. If the cruise still does not work the only other thinf you can do without the scan tool it check the fuses, make sure the speedometer is working and make sure your brake lights are not stuck on. Other than this you need the scan tool to diagnose the system. I hope this helps. An accept would be appreciated.
