Turn signal flash fast then slow

1989 Cadillac Deville turn signal lights on both right and left side flash fast then slow.I have check all light bulbs for faulty or burnt all are good. I have pulled the flasher relay from under the dash and replaced it with a new one but lights continue to flash fast then slow. I turned on hazard lights and they function normally.does the hazard light have a separate relay from the turn signal or do they share one relay. How can I resolve this problem of fast and slow signals? Any help would be greatly appreciated.