have you recently been in an accident? is the light continuously on or comes on and go again? you do mention coming on again and again but does it go off at all ... might be a problem with your car's control unit ... in any case .. you shouldn't be driving the car when this kind of light is on. Telling you out of experience.
Something which does not seem to grab most peoples' attention is the fact that a vacuum leak could very well cause the actuator to not function correctly. You should check into the vacuum lines if nothing else works.