Just to complete this thread here's what happened:

Turns out that my battery, yes my battery, was defective. There was no indication that he battery was dying (other than it was low one morning) and no batt lamp lit on the dash (yes it does function as the lamp came on 1 week before when the idle pulley bearings blew out and the serpentine belt went flying off). Apparently when the ABS kicks in it requires significant current (hence the 60amp fuse). Since the battery was defective it couldn't supply the necessary current and the ABS lamp would kick on. Swapped the battery a week ago for a new one and everything is running fine. Tested the ABS on a gravel road and it is functioning normally.