flashing/blinking battery light

okay, so i have a 1999 contour LX 4 door, and i have a friggin problem. First, i have changed everything from the engine block up because it was done for. I changed the head, gears, cams, water pump, air filter, changed the oil and filter, serpentine belt, timing belt, alternator, battery, the ground wire, and the positive wire that goes from the battery, to a huge friggin fuse, then to the starter or something. but i basically changed the positive wire. I changed the wiring because the battery light flashes or blinks when get at high rpm's. I got the alternator checked for a charge, and it charges at 14.4 (rough guess) something, and the connection to the battery says that the battery gets 14.2(another rough guess), then under load, heat on, rear defrost on, radio on, headlights w/ high end fog lights on. and the alt charges at like 15 something then the drop to the batters is less than .5 or so. SO I HAVE NO FRIGGIN IDEA WHY THE BATTERY LIGHT KEEPS BLINKING OR FLASHING OR WHAT EVER. BUT IT ONLY HAPPENS AT HIGH RPM'S. Its a manual and it has like 150k mileage on it. and the clutch is new also. help me por favor!!!!!!!!