Whenever the light is ON the ABS is meant to revert to normal braking..........i.e skidding.!!!! You shouldntve had a brake failure!
Check your front disk rotors to see if the ABS rings are full of dirt/grime/metal etc and clean out.
check battery terminals and wiring is clean & tight.
check fluid level
try driving on a quiet straight bit of road and jump on the brakes to test the ABS:
if skids = ABS Fingered:(
If no skid but pedal pulse = ABS OK (currenlty)
Otherwise go to ford and get codes checked!
:p