Turn signals have a relay (its a small switch that charges and discharges current) which controls your turn signals blinking speed and interval. This is most likely your problem. You should be able to get a new one at your local parts store. Follow these instructions, in this order, and let me know how it works.
Step 1:Turn on the hazard lights and walk around the Taurus
checking that all four turn signal lights are working. If any of them are not working, replace the bulbs. A non-working bulb in any of the turn signals will often make the turn signals appear that a flasher is going bad.
Locate the fuse box and check the fuses for the turn signals. There may be more than one. Replace any fuses that are blown and then recheck the turn signals again. If they still aren't working properly, then move on to replace the flasher.
Look for a round, silver-colored object near the fuse box. Put your finger on the object and turn on the turn signal. You should be able to feel a mechanical clicking as the turn signal blinks. This is the flasher.
Pull the silver flasher out of the socket and replace it with the new one. Each of the flashers should have two pins sticking out of the bottom side. Start the Taurus and recheck the turn signals to ensure that they work.