Muti-Function Switch (MFS) replacement. Not a hard DIY.
Clock spring is related to air-bag, not turn signals. (PS, it's not really a spring either.)
Multi-Function Switch (MFS) Problems
Common Symptoms: Headlights don't work (highs and/or lows), wipers don't work correctly, turn signals don't work correctly, hazards don't work correctly, any combination requiring moving the MFS or turning on another feature to get one feature to work.
Do you have the same problem as the OP? If so, the only other issues I can think of are: a bad flasher, a short in the wiring or a light socket, or a possible blockage in the steering column preventing the arm from returning to the middle (off) position. Was the MFS that you just installed new or used?
I have researched this problem before, in fact my friend had the same problem with his Taurus(turn signal not cancelling) it was suggested on a few different sites, to use some wd-40 sprayed into the 4 way flasher opening and working the flasher. It cured his turn signal problem quickly, and for minimal cost!!